Abstract:
Systems, methods, and computer program products for annotating documents are described herein, wherein in some embodiments the documents are immutable. The method operates by enabling a user to place an application in an annotation mode. An annotation is created, and then linked to a portion of an immutable data object. Location information is displayed proximate to the annotation mode location information indicates a location of the linked portion in the data object.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of Ser. No. 08/632,801 filed Apr. 17, 1996, is now U.S. Pat. No. 5,806,079 allowed, which is a continuation-in-part of Ser. No. 08/423,676, filed Apr. 18, 1995, now U.S. Pat. No. 5,623,679 issued on Apr. 22, 1997, which is a continuation-in-part of Ser. No. 08/341,129, filed Nov. 18, 1994, abandoned, which is a continuation-in-part of Ser. No. 08/155,752, filed Nov. 19, 1993, now U.S. Pat. No. 5,623,681 issued on Apr. 22, 1997. U.S. Pat. Nos. 5,623,679 and 5,623,681 and Ser. No. 08/341,129 and 08/632,801 are herein incorporated by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to organizing, linking, and maintaining disparate data objects. More particularly, the invention relates to organizing, linking, and maintaining disparate data objects using an intelligent and powerful note engine. 
     2. Related Art 
     Data Organization 
     In today&#39;s Computer Age, there exists a vast amount of information that can be processed by computers. Such information is generally referred to herein as data objects. 
     There are many computer applications and computer-related devices for generating and processing data objects, such as word processing applications, spreadsheet applications, presentation managers, database managers, financial applications, networking applications, communication applications, sound recorders and processors, video recorders and processors, on-line service applications, scanners, computer aided drafting (CAD) applications, etc. As will be appreciated, the data objects generated and processed by these applications and devices vary widely in subject matter. Also, these data objects come in many forms, such as text files, image files, video files, audio files, etc. Accordingly, these data objects are disparate in both form and content. 
     It is often desirable to organize information such that data objects that somehow relate to a particular topic are associated with other data objects that are related to the same topic. Hyperlinks represent a conventional mechanism for associating data objects with other data objects. FIG. 1 illustrates a scenario involving Documents A, B, C, D, and E. Document A is linked to Document B via Hyperlink B. In a similar manner, Document B is linked to Documents C and D, and Document D is linked to Document E. A user follows Hyperlinks B, C, D, and E to traverse through Documents A, B, C, D, and E using a conventional “point-and-click” methodology. 
     As apparent from FIG. 1, Hyperlinks B, C, D, and E form a trail through Documents A, B, C, D, and E. This trail represents the organization of Documents A, B, C, D, and E. However, Hyperlinks B, C, D, and E do not document or explain this trail. Accordingly, it can be said that Hyperlinks B, C, D, and E form an undocumented trail through Documents A, B, C, D, and E. 
     Consider, for example, Hyperlink B. Hyperlink B merely serves to link Document A to Document B. Hyperlink B does not describe why Document A is linked to Document B. Instead, the explanation or rationale for the linkage of Document A with Document B must be inferred by the user from the contents of Documents A and B. 
     However, it is often difficult to discern the rationale for the linkage between data objects. This is especially true for data objects which are not directly linked (Documents A and B represent two data objects that are directly linked), but which are indirectly linked (Documents A and E represent two data objects that are indirectly linked). For example, it may be very difficult for a user to determine the rationale for the indirect linkage of Document E to Document A. To discern the rationale for this linkage, it may be necessary for the user to review the contents of Documents A, B, D, and E. This could be a difficult and time-consuming task. Even then, the user may not be able to determine the rationale for the linkage. The user is unable to discern this rationale by reference to Hyperlinks B, D, and/or E since, as discussed above, these hyperlinks do not convey any information to the user. 
     In addition, a user will not know of the existence of Document E when following traditional links from Document A until he/she gets to Document E. This link (from Document A to Document E) may be the only link of interest to the user. The traditional linking mechanism is wasteful, as it requires the user to traverse through Documents B and D in order to arrive at Document E. Also, the user may end the search at Document B or Document D, thereby never getting to Document E. Further, traditional linking mechanisms do not provide a means by which to create links, with contextual information within and between different data objects. This type of linkage would provide the user with critical information as to how and why data objects are internally and externally related. Also, traditional links fail to provide the user with the ability to link the same portion of a data object with multiple links and notes to other data objects as well as to other portions of the same data object with varying contextual information on the rational for the links and user ideas or comments on the portion of the linked data object. 
     Accordingly, there is a need for a mechanism that not only organizes, associates, and links data objects internally and externally, but also conveys contextual information explaining the rationale for such organization, association, and linkage, as well as the users&#39; thoughts regarding the data objects. 
     Adding Notes to Data Objects 
     It is often desirable to add notes to data objects. Such notes may include a description of the contents of the data objects, instructions or comments to people working with the data objects, project notes, etc. 
     Some computer applications allow users to attach notes to data objects. For example, some word processors (such as MICROSOFT WORD and WORD PERFECT) allow users to attach notes to their documents. Typically, the user positions the cursor at the point in the document where he wishes to insert the note. The user then keys in the text for the note. The note is linked to the point in the document where the cursor was positioned. 
     Some spreadsheet applications (such as MICROSOFT EXCEL) allow users to attach notes to their spreadsheets. FIG. 2 illustrates an example spreadsheet window  204 . The user has attached a note  212  to cell  206  of the spreadsheet  204  via a link  210 . A small icon  208  located in cell  206  indicates that a note (in this case, note  212 ) is linked to cell  206 . The user accesses the note  212  from the spreadsheet  204  by clicking on the icon  208 . 
     The note functionality of conventional computer applications (including those described above) is limited in many respects. First, these applications restrict the manner in which users are allowed to associate notes with data objects. For example, these applications permit a note to be associated with only a single element in a data object. See FIG. 2, where note  212  is associated with only cell  206 . It is not possible to associate note  212  with multiple cells or to establish intra or inter data object links. Also, notes cannot be associated with partial overlapping portions of data objects. For example, the spreadsheet  204  in FIG. 2 does not allow a first note to be associated with cells  206  and  214 , and a second note to be associated with cells  214  and  216 . 
     Second, these applications do not allow users to group related notes together. Accordingly, these applications do not permit users to organize their notes. 
     Third, these applications do not provide a mechanism for documenting the rationale for linking notes to data objects. For example, in FIG. 2, the link  210  conveys no information that explains the rationale for linking note  212  with cell  206 . Instead, the user must attempt to discern this rationale from the contents of note  212  and cell  206 . 
     Fourth, these applications do not provide a mechanism for establishing intra or inter data object linking, such as between different spreadsheets in EXCEL or linking with a word processor data object or another computer application data object. 
     The restrictions described above severely diminish the usefulness of notes. Notes are intended to convey information. The ability of notes to convey information is diminished if notes cannot be associated with any portions of data objects, and if notes cannot be organized and structured, and if the rationale for linking notes to data objects is not explicitly conveyed to users. 
     Accordingly, there is a need for a more flexible and intelligent mechanism for attaching notes to data objects. 
     Potential Loss of Information 
     Given these limitations of conventional data organization and note tools, users are not motivated or encouraged to utilize computer related tools to organize work product and data objects that are collected and generated during the performance of a task or project. Instead, such work product and data objects are often maintained in an unorganized state, often scattered about a person&#39;s office or haphazardly stored in a makeshift filing system. Also, a person&#39;s thinking is not typically documented or recorded. Instead, such thinking remains in the person&#39;s head. 
     Thus, a person&#39;s thinking, work product, and data objects that are collected and generated during the performance of a task or project are easily lost (either temporarily or permanently) if the person becomes unavailable, is unable to completely remember his thinking, or loses his work product. The person and the person&#39;s employer then suffer from this loss of information. 
     Accordingly, what is required is a system and method for enabling the organization and recordation of a person or group&#39;s thinking, work product, and data objects collected or generated during a project or task. Such organization and recordation serves to institutionalize the person or group&#39;s thinking, work product, and data objects, thereby protecting against the unavailability of persons, memory loss, or loss of work product. 
     SUMMARY OF THE INVENTION 
     Generally speaking, the present invention is directed to a system and method of linking notes to data objects. The invention enables a user to select a portion of a data object associated with an application. The invention creates a sub-note in a note, and links the sub-note to the selected portion. The invention receives a request from a user viewing the note to display the selected portion linked to the sub-note. In response to this request, the invention invokes the application, if the application is not already invoked, and causes the application to load the data object and present the selected portion. 
     Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     The present invention will be described with reference to the accompanying drawings, wherein: 
     FIG. 1 illustrates a conventional scenario comprising linked documents; 
     FIG. 2 illustrates a conventional spreadsheet application having limited note capabilities; 
     FIG. 3A is a block diagram of a notes application according to a preferred embodiment of the present invention; 
     FIG. 3B is a block diagram used to explain the linking capabilities of the present invention; 
     FIGS. 4,  6 A,  6 B,  7 A,  7 B,  8 ,  9 ,  10 ,  11 ,  12 , and  13  illustrate example screen displays generated by the present invention; 
     FIG. 5 is a legend of colors/fonts and symbols used by the present invention; 
     FIGS. 14 and 15 is a block diagram of a notes database according to an embodiment of the present invention; 
     FIG. 16 illustrates a note menu of the present invention; 
     FIGS. 17,  18 ,  19 ,  20 ,  21 ,  22 ,  23 ,  24 ,  25 ,  26 ,  27 ,  39 , and  40  are flowcharts depicting the preferred operation of the present invention; 
     FIG. 28 is a block diagram of an exemplary computer system useful for implementing the present invention; 
     FIG. 29 illustrates an example link view; 
     FIG. 30 illustrates an example note view; 
     FIG. 31 illustrates an example object view; 
     FIG. 32 illustrates an example icon view; 
     FIG. 33 illustrates the results of a replication operation; 
     FIG. 34 is a block diagram illustrating the effects of a user interface of the present invention; 
     FIG. 35 illustrates an example virtual reality environment; 
     FIG. 36 is an additional block diagram of the notes database; 
     FIGS. 37 and 38 illustrate distribution of the notes database; 
     FIGS. 41 and 42 illustrate a medical related example; 
     FIG. 43 illustrates an example display where multiple views are displayed; 
     FIG. 44 illustrates the effect of security/privacy features of the invention; 
     FIG. 45 is a block diagram of a note grouping table; 
     FIG. 46 illustrates a movie making example; and 
     FIG. 47 illustrates a bar review course materials example. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     
       
         
               
             
               
               
             
               
               
               
             
               
               
               
               
             
               
               
               
             
               
               
               
               
             
               
               
               
               
             
               
               
               
               
             
               
               
               
               
             
               
               
               
               
             
               
               
               
               
             
               
               
               
               
             
               
               
               
             
               
               
               
               
             
               
               
               
             
               
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Table of Contents 
               
             
          
           
               
                   
                 Page 
               
               
                   
                   
               
             
          
           
               
                 1. 
                 Overview of the Invention 
                 11 
               
             
          
           
               
                   
                 1.1 
                 Medical Example 
                 12 
               
             
          
           
               
                 2. 
                 Structure of the Present Invention 
                 17 
               
               
                 3. 
                 Features and Capabilities of the Present Invention 
                 20 
               
             
          
           
               
                   
                  3.1 
                 Note/Sub-Note Organization 
                 20 
               
               
                   
                 3.2 
                 Linking Sub-Notes To Data Objects 
                 21 
               
               
                   
                 3.3 
                 Examples of Note/Sub-Note Organization and Linking 
                 25 
               
               
                   
                   
                 Sub-Notes To Data Objects 
               
               
                   
                 3.4 
                 Viewing Notes, Sub-Notes, and Data Objects 
                 32 
               
             
          
           
               
                   
                 3.4.1 
                 Note View 
                 33 
               
               
                   
                 3.4.2 
                 Object View 
                 35 
               
               
                   
                 3.4.3 
                 Link View 
                 36 
               
               
                   
                 3.4.4 
                 User-Defined View 
                 37 
               
             
          
           
               
                   
                 3.5 
                 Editing Note/Sub-Note Organization 
                 38 
               
             
          
           
               
                   
                 3.5.1 
                 Modification 
                 38 
               
               
                   
                 3.5.2 
                 Replication 
                 39 
               
             
          
           
               
                   
                 3.6 
                 User Interface 
                 40 
               
               
                   
                 3.7 
                 Security 
                 42 
               
             
          
           
               
                   
                 3.7.1 
                 Security on Individual Note Groupings, Notes, 
                 43 
               
               
                   
                   
                 Sub-notes, Links, and Data Objects 
               
               
                   
                 3.7.2 
                 Security on the Note Database as a Whole 
                 44 
               
             
          
           
               
                   
                 3.8 
                 Search Capabilities 
                 46 
               
             
          
           
               
                 4. 
                 Notes Database 
                 47 
               
               
                 5. 
                 Operation of the Invention 
                 52 
               
             
          
           
               
                   
                 5.1 
                 Launch an Application 
                 54 
               
               
                   
                 5.2 
                 Create a Note/Sub-note (From the Note Menu) 
                 54 
               
               
                   
                 5.3 
                 Create a Note/Sub-note (Using a Pen) 
                 59 
               
               
                   
                 5.4 
                 View Note (By Selecting a Linking Button in a Data 
                 61 
               
               
                   
                   
                 Object) 
               
               
                   
                 5.5 
                 View Note (From the Note Menu) 
                 62 
               
               
                   
                 5.6 
                 Select View 
                 66 
               
               
                   
                 5.7 
                 Modify Privacy/Security Settings 
                 69 
               
               
                   
                 5.8 
                 Find Note/Sub-note 
                 69 
               
               
                   
                 5.9 
                 Edit One or More Notes 
                 70 
               
             
          
           
               
                 6. 
                 Applications of the Invention 
                 71 
               
             
          
           
               
                   
                 6.1 
                 Movie Production 
                 71 
               
               
                   
                 6.2 
                 Bar Review Program 
                 73 
               
             
          
           
               
                 7. 
                 Conclusion 
                 75 
               
               
                   
               
             
          
         
       
     
     1. Overview of the Invention 
     The present invention is directed to a system and method for attaching notes to data objects, and for linking data objects via the use of notes. The note capabilities of the present invention can be used to organize, associate, annotate, and link data objects in an intra and/or inter data object environment with single notes and multiple subnotes and/or multiple notes and subnotes to the same data object portions or different data object portions as required by the needs of the user to institutionalize his/her knowledge. Additionally, the note capabilities of the present invention can be used to convey information explaining the rationale for such organization, association, and linkage. Accordingly, the present invention represents a system and method for using intelligent notes to organize, associate, annotate, and link data objects. The invention can also be used to manipulate these data objects. 
     As used herein, the term “object” refers to any information in any form that can be accessed and/or processed by a computer. Such information includes data generated and/or processed by computer applications and computer-related devices such as word processing applications, spreadsheet applications, presentation managers, database managers, financial applications, networking applications, communication applications, sound recorders and processors, video recorders and processors, on-line service applications, scanners, computer aided drafting (CAD) applications, virtual reality applications and environments, etc. The data objects generated and processed by these applications and devices vary widely in subject matter. Also, these data objects come in many forms, such as text files, image files, video files, audio files, computer programs, etc. Accordingly, these data objects are disparate in both form and content. 
     The invention is adapted to memorialize and/or institutionalize a person&#39;s or group&#39;s thinking and work product regarding a subject. If a person&#39;s or group&#39;s thinking and work product are not memorialized or institutionalized, then such thinking and work product may be lost or not accessible when needed if the person or group becomes unavailable, or is unable to remember its thinking, or loses its work product. 
     1.1 Medical Example 
     The invention shall initially be described by way of an example. Consider a scenario where a doctor is attempting to determine the reasons for a patient&#39;s recent health problems involving numbness in the legs. Referring to FIG. 41, the doctor first reviews the patient&#39;s record  4102 . The doctor notices that the patient has high blood pressure. The doctor also notices that the patient has been taking Drug X for approximately one year (for a reason other than high blood pressure). The doctor speculates that Drug X, high blood pressure, and numbness in the legs are related to one another. The doctor&#39;s review of the patient record  4102  and his speculation regarding Drug X, high blood pressure, and numbness in the legs represent the doctor&#39;s thinking  4116 . The doctor may or may not record this thinking  4116 . 
     The doctor then consults the Physician&#39;s Desk Reference (PDR)  4104  to see if it has an entry on Drug X. The PDR  4104  has a short entry on Drug X. This entry indicates that Drug X is a new drug (which is the reason for the short entry in the PDR), and lists the manufacturer of Drug X. The doctor decides that he needs to contact this drug manufacturer. This decision of the doctor constitutes the doctor&#39;s thinking  4118  regarding the PDR  4104 . The doctor may or may not record such thinking  4118 . 
     The doctor contacts the drug manufacturer. The drug manufacturer sends Drug X product literature  4106  to the doctor. The doctor reviews the product literature  4106 . The product literature  4106  indicates that there have been some studies linking Drug X with heart problems. The doctor begins to suspect that Drug X combined with high blood pressure results in some type of heart problems. The doctor&#39;s suspicions represent his thinking  4120  regarding the product literature  4106 . The doctor may or may not record such thinking  4120 . 
     The doctor then watches a video tape  4110  of a news story on the drug manufacturer. The news story indicates that, in the past, drugs made by the drug manufacturer have had adverse and unexpected side effects. This news story supports the doctor&#39;s suspicion that Drug X made by the drug manufacturer may have adverse effects when taken by patients with high blood pressure. The doctor&#39;s thinking on the video tape  4110  is represented by thinking  4124 , which may or may not be recorded. 
     The doctor then pulls the records of people who have previously taken Drug X. Such records are indicated as  4108  in FIG.  41 . The records  4108  indicate that some people taking Drug X subsequently developed heart problems. Only some of these people, however, previously had high blood pressure. The doctor decides to order the EKG records  4112  of his patient and also of the people who had high blood pressure, took Drug X, and subsequently developed heart problems. The doctor&#39;s thinking in this regard is represented by thinking  4122 , which may or may not be recorded. 
     The doctor reviews the EKG records  4112  of the people who had high blood pressure, took Drug X, and subsequently developed heart problems. The doctor notices a slight heart murmur in these people. This heart murmur developed approximately one year after the people started taking Drug X. These people suffered severe heart attacks approximately six months after the development of the heart murmurs. The doctor theorizes that Drug X, when taken by people with high blood pressure, eventually causes severe heart problems. Such heart problems begin with slight heart murmurs approximately one year after taking Drug X, and conclude with a severe heart attack approximately six months thereafter. The doctor speculates that the heart murmurs could cause numbness in a person&#39;s legs, which is the symptom that his patient is experiencing. The doctor&#39;s thinking in this regard is represented by thinking  4126  and conclusions  4114 , which may or may not be recorded. 
     The doctor recalls that his patient has been taking Drug X for approximately one year. The doctor reviews his patient&#39;s EKG, and notices that slight heart murmurs have begun. The doctor immediately instructs his patient to stop taking Drug X. 
     The scenario described above and shown in FIG. 41 represents a conventional investigation, analysis, and decision process. This conventional process may or may not be documented. In particular, the doctor&#39;s thinking during each step of the process may or may not be documented. Such thinking is represented by blocks  4116 ,  4118 ,  4120 ,  4122 ,  4124 ,  4126 , and  4114 . The doctor may document such thinking (by writing or dictating notes, for example). However, the doctor is just as likely to maintain his thinking only in his head. In this latter case, the doctor&#39;s thinking will be lost or not accessible when needed if the doctor becomes unavailable, or is unable to remember his thinking. 
     The investigation, analysis, and decision process represented by FIG. 41 will not be fully documented, even if the doctor documents his thinking in blocks  4116 ,  4118 ,  4120 ,  4122 ,  4124 ,  4126 , and  4114 . In other words, the total work product and thinking resulting from the investigation, analysis, and decision process of FIG. 41 will not be fully documented simply by the documentation of thinking blocks  4116 ,  4118 ,  4120 ,  4122 ,  4124 ,  4126 , and  4114 . This is the case for at least two reasons. First, such documentation will be very disorganized. The documentation will not indicate how one note is related to another note. Second, such documentation will include only the doctor&#39;s thinking (represented by blocks  4116 ,  4118 ,  4120 ,  4122 ,  4124 ,  4126 , and  4114 ). The documentation will not include the source materials upon which such thinking was based or a reference to the exact portion (text excerpt, video section, audio segment, etc.) that is relevant to the doctor&#39;s thinking and analysis. In instances with voluminous source material, the lack of this type of reference or the like prevents the doctor from clearly communicating and recording the basis for the analysis. That is, the documentation will not include the patient record  4102 , the entry of the PDR  4104  dealing with Drug X, the product literature  4106 , the records  4108  of people who took Drug X, the video  4110  on the drug manufacturer, or the EKG records  4112 . The documentation may contain cites to some of these data objects, but it would be necessary for a person to manually retrieve these data objects in order to evaluate them. Such manual retrieval is inefficient, as it requires another person to perform the same tasks as the doctor. Also, such manual retrieval may not be possible, since source materials often become unavailable over time. Further, as noted above, such cites will not be to the exact portion (text excerpt, video section, audio segment, etc.) that is relevant to the doctor&#39;s thinking and analysis. 
     The invention addresses and solves the problems illustrated by the conventional investigation, analysis, and decision process of FIG.  41 . The invention is adapted to memorialize and/or institutionalize the doctor&#39;s total work product and thinking related to the investigation, analysis, and decision process. By doing so, the invention ensures that the doctor&#39;s total work product and thinking will survive and be accessible when needed, even if the doctor becomes unavailable, or is unable to remember his thinking, or loses the hard copies of his work product. 
     The operation of the invention is represented by FIG.  42 . The invention allows the doctor to create a note  4201  comprising multiple sub-notes  4202 ,  4204 ,  4206 ,  4208 ,  4210 ,  4212 ,  4214 . The doctor records his thinking in these sub-notes  4202 ,  4204 ,  4206 ,  4208 ,  4210 ,  4212 ,  4214 . For example, according to the present invention, the doctor reviews the patient&#39;s record  4102  and notices that the patient has high blood pressure. The doctor also notices that the patient has been taking Drug X for approximately one year (for a reason other than high blood pressure). The doctor speculates that Drug X, high blood pressure, and numbness in the legs are related. The doctor records his thinking regarding the patient record  4102  and the potential relationship between Drug X, high blood pressure, and numbness in the legs in sub-note  4202 . 
     The sub-notes  4202 ,  4204 ,  4206 ,  4208 ,  4210 ,  4212 ,  4214  are linked to the relevant portions of the source materials upon which the doctor&#39;s thinking is based. Such linkage is represented by links  4230 ,  4232 ,  4234 ,  4236 ,  4238 ,  4240 , and  4242 . For example, the doctor links sub-note  4202  to the relevant portion of the patient&#39;s record  4102 . As another example, recall that the doctor consults the Physician&#39;s Desk Reference (PDR)  4104  to see if it has an entry on Drug X. The PDR  4104  has a short entry on Drug X. This entry indicates that Drug X is a new drug (which is the reason for the short entry in the PDR), and lists the manufacturer of Drug X. The doctor decides that he needs to contact this drug manufacturer. The doctor records his thinking regarding the Drug X entry in the PDR  4104  in sub-note  4204 . The doctor links sub-note  4204  to that relevant portion of the PDR  4104  containing the entry on Drug X. By linking sub-note  4204  to only the relevant portion of the PDR  4104  pertinent to the doctor&#39;s thinking recorded in sub-note  4204 , the doctor&#39;s creates a documented trail that is more useful and effective at communicating his work product and thinking. 
     The sub-notes  4202 ,  4204 ,  4206 ,  4208 ,  4210 ,  4212 ,  4214  and the links  4230 ,  4232 ,  4234 ,  4236 ,  4238 ,  4240 ,  4242  collectively represent the doctor&#39;s total work product and thing. The sub-notes  4202 ,  4204 ,  4206 ,  4208 ,  4210 ,  4212 ,  4214  and the links  4230 ,  4232 ,  4234 ,  4236 ,  4238 ,  4240 ,  4242  are stored in a computer database. Thus, the invention memorializes and/or institutionalizes the doctor&#39;s total work product and thinking. 
     The invention is preferably implemented using a notes application  302  (FIG.  3 ). The notes application  302  is described in the following section. 
     2. Structure of the Present Invention 
     FIG. 3A is a block diagram of a notes application  302  according to a preferred embodiment of the present invention. The notes application  302  includes a user interface  304 , a notes engine  306 , and a notes database  308 . The notes database  308  includes notes and sub-notes (also called note sections) that are attached to data objects generated and/or processed by computer applications  312 . The computer applications  312  include any computer applications that generate and/or process information, such as word processing applications, spreadsheet applications, presentation managers, database managers, financial applications, networking applications, communication applications, sound processors, video processors, on-line service applications, computer aided drafting (CAD) applications, etc. 
     The notes engine  306  manages the notes database  308 . More particularly, the notes engine  306  enables users to create, modify, delete, link, view, and otherwise manipulate the notes and sub-notes in the notes database  308 . Users gain access to the functions supported by the notes engine  306  via the user interface  304 . 
     In performing its function, the notes application  302  drives, controls, manipulates, and otherwise interacts with the computer applications  312 . For example, the notes application  302  controls the applications  312  so as to open data objects (i.e., open files containing data objects), display particular portions of data objects, highlight portions of data objects using particular fonts, patterns, and/or colors, display icons and/or buttons, etc. 
     Preferably, the present invention achieves this functionality by interacting with applications  312  that support an interface  310  defining the interaction between computer applications. Preferably, the interface  310  uses the Object Linking Embedded (OLE) standard. The OLE standard is well known and defines the manner in which one software application may drive, control, manipulate, and otherwise interact with another software application. The OLE standard is described in many publicly available documents, such as  Microsoft OLE Programmers Reference,  Volumes I and II, 1993, which are herein incorporated by reference in their entirety. 
     It should be understood that the invention is not limited to use with OLE components. The applications  312  can be any conventional or implementation specific applications, as long as they have the capability of being externally controlled (in this case, as long as they have the capability of being controlled by the notes application  302 ). 
     Standard windows operations are mentioned in this disclosure. Such operations include selecting text, opening files, moving between windows, resizing windows, editing documents, etc. Such operations are well known and are described in many publicly available documents, such as  Microsoft Word for Windows Users Guide,  1994, incorporated herein by reference in its entirety. 
     In an embodiment of the present invention, components of the present invention (such as the notes application  302 ) are each implemented using a computer system  2802  such as that shown in FIG.  28 . The computer system  2802  includes one or more processors, such as a processor  2804 . The processor  2804  is connected to a communication bus  2806 . The computer system  2802  also includes a main or primary memory  2808 , preferably random access memory (RAM). The primary memory  2808  has stored therein control logic  2810 , such as software corresponding to the notes application  302 , and the notes database  308 . 
     It should be understood that the notes database  308  is not necessarily stored within a single computer. Instead, the notes database  308  may be distributed among multiple computers. Such distribution of the notes database  308  is described in further detail below. 
     The computer system  2802  also includes a secondary memory  2812 . The secondary memory  2812  includes, for example, a hard disk drive  2814  and/or a removable storage drive  2816 , representing a floppy disk drive, a magnetic tape drive, a compact disk drive, a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as EPROM or PROM), etc., which is read by and written to by removable storage unit  2818 . As will be appreciated, the removable storage unit  2818  includes a computer usable storage medium having stored therein computer software and/or data. The removable storage drive  2816  reads from and/or writes to a removable storage unit  2818  in a well known manner. Removable storage unit  2818 , also called a program storage device or a computer program product, represents a floppy disk, magnetic tape, compact disk, etc. 
     Computer programs (also called computer control logic) are stored in main memory  2808  and/or the secondary memory  2812 . Such computer programs, when executed, enable the computer system  2802  to perform the functions of the present invention as discussed herein. In particular, the computer programs, when executed, enable the processor  2804  to perform the functions of the present invention. Accordingly, such computer programs represent controllers of the computer system  102 . The notes application  302  preferably represents a computer program executing in the computer system  2802 . 
     The computer system  2802  also includes a communication interface  2820 . The communications interface  2820  enables the computer system  2802  to communicate and interact with locally or remotely located external devices  2824  via a communications medium  2822 . In particular, communications interface  2820  enables the computer system  2802  to send and receive software and data to/from the external devices  2824 . Examples of the communications interface  2822  include a modem, a network interface (such as an Ethernet card), a communications port, etc. 
     The computer system  2802  also includes a display unit  2826 , such as a computer monitor, and one or more input devices, such as a keyboard and a pointing device (such as a mouse, trackball, etc.). 
     In one embodiment, the invention is directed to a system  2802  as shown in FIG. 28, and having the functionality described herein. In another embodiment, the invention is directed to a computer program product having stored therein computer software (having the functionality described herein) for controlling computer systems, such as computer system  2802 . In another embodiment, the invention is directed to a system and method for transmitting and/or receiving computer software (having the functionality described herein) to/from external devices  2824 . 
     3. Features and Capabilities of the Present Invention 
     The present invention includes a multitude of features and capabilities which enable it to achieve the advantages discussed herein. Many of these features and capabilities are discussed in the following sections. 
     3.1 Note/Sub-Note Organization 
     The present invention supports a note/sub-note hierarchy, where a note may include zero or more sub-notes. This is shown in FIG. 29, for example, where Note A includes Sub-notes A, B, and C. Note B includes Sub-notes B and C (dashed line  2950 B is discussed below), Note C includes Sub-notes B, D, and E, and Note D includes Sub-notes E and F. 
     The note/sub-note hierarchy is useful for organizing information. In particular, the note/sub-note hierarchy allows users to group together related sub-notes for organization purposes. Related sub-notes may be grouped together under one note. 
     The note/sub-note hierarchy is extendable to multiple levels. For example, related notes can be grouped together under a note grouping. In FIG. 29, for example, Notes A and B are grouped together under Note Grouping A. Notes B, C, and D are grouped together under Note Grouping B. It should be understood that the invention is not limited to the three level hierarchy shown in the example of FIG.  29 . The invention is extendable to more than three levels. 
     The note/sub-note hierarchy of the invention is very flexible. Multiple note groupings may include the same note. For example, both Note Groupings A and B include Note B. Also, multiple notes may include the same sub-note. For example, Notes A, B, and C include Sub-note B. 
     The note/sub-note hierarchy is defined by users. That is, users define which notes are contained in note groupings, and which sub-notes are contained in notes. The invention includes tools for enabling users to define and modify the note/sub-note hierarchy (such tools are discussed below). 
     3.2 Linking Sub-Notes To Data Objects 
     The present invention allows users to link sub-notes to portions of data objects. In FIG. 29, for example, Sub-note A is linked to a portion of Data Object A via link  2911 . As discussed above, a data object represents any information in any form that can be accessed and/or processed by a computer. The data objects generated and processed by these applications and devices vary widely in subject matter. Also, these data objects come in many forms, such as text files, image files, video files, audio files, computer programs, etc. Accordingly, these data objects are disparate in both form and content. 
     Users can navigate from sub-notes to data objects via the links. For example, a user can navigate from Sub-note A to Data Object A via link  2911 . 
     The links between sub-notes and data objects are bidirectional. Thus, in addition to being able to navigate from sub-notes to data objects via the links, users can also navigate from data objects to sub-notes via the links. For example, a user can navigate from Data Object A to Sub-note A via link  2911 . 
     A sub-note may be linked to all or any portion of a data object. Multiple sub-notes may be linked to portions of the same data object. This is true, whether the sub-notes are in the same or different notes. These data object portions may be completely overlapping, partially overlapping, or non-overlapping. Also, the sub-notes in a note may be linked to portions of a single data object, or to portions of one or more data objects. 
     A data object may be linked to one or more sub-notes (these sub-notes may be in the same note, or in multiple notes). In FIG. 29, for example, data object A is linked to Sub-notes A, C, and D. 
     Users can navigate from sub-notes in a first note to sub-notes in a second note via common data objects. In FIG. 29, for example, a user can navigate from Sub-note A in Note A to Sub-note D in Note C via Data Object A, which is linked to both Sub-note A (via link  2911 ) and Sub-note D (via link  2917 ). 
     The linking capabilities of the present invention shall be further described by reference to an example scenario presented in FIG.  3 B. The notes application  302  in the example of FIG. 3B includes notes  314 A and  314 B (these notes are stored in the notes database  308 , which is not explicitly shown in FIG.  3 B). Each note  314  includes a plurality of sub-notes  316 . 
     Each sub-note  316  is linked to a data object  320 . Each data object  320  is associated with one or more applications  312 . A data object  320  is associated with an application  312  if the application  312  is capable of accessing and/or processing the data object  320 . More particularly, each sub-note  316  is linked to a portion  322  of a data object  320 . A portion  322  may include all or part of a data object  320 . Portions  322  in the same data object  320  that are linked to sub-notes  316  may be distinct (non-overlapping), may completely overlap, or may partially overlap. 
     For purposes of illustration, it is assumed herein that each data object is associated with a single computer program application. This association between data objects and applications may be established in any well known manner, such as by file extension. For example, all files having a “wpd” extension are as a default associated with the WORD PERFECT word processing application, all files having a “wks” extension are as a default associated with the LOTUS 1-2-3 spreadsheet application, all files having a “db” extension are as a default associated with the PARADOX database application, etc. These default associations between data objects and applications are preferably user definable. Preferably, users may override these default associations at the time that a sub-note is linked with a data object, or at any time thereafter. 
     A note  314  may contain sub-notes  316  that are linked to portions  322  of a single data object  320 , or multiple data objects  320 . These data objects  320  may be associated with a single application  312 , or with multiple applications  312 . For example, note  314 A includes sub-notes  316 A,  316 B,  316 C that are linked to portions  322 A,  322 C,  322 B, respectively, of data objects  320 A,  320 B that are associated with application  312 A. Note  314 A also includes a sub-note  316 D that is linked to portion  322 D of object  320 C associated with application  312 B. 
     Multiple sub-notes  316  in the same or different notes  314  may be linked to the same portion  322  of a data object  320 . For example, sub-notes  316 D and  316 F are linked to portion  322 D of object  320 C. 
     A note  314  represents a data object. Accordingly, a sub-note  316  may be linked to a portion of a note  314 . For example, sub-note  316 E is linked to portion  322 F of note  314 B. Portion  322 F includes sub-note  316 G. 
     Each sub-note  316  includes a content field  1512  (FIG. 15) that is used to convey information. The contents of the content field  1512  are user definable. Preferably, the content field  1512  includes at least information that explains the rationale for linking the sub-note  316  to the portion  322  of the data object  320 . For example, the content field  1512  could include a description of how the portions  322  linked to the sub-notes  316  in the note  314  are related to one another. The content field  1512  can be any format or combination of formats, such as text, sound, video, image, executable program, tactile (such as braille), etc. 
     The mechanism for linking portions  322  of data objects  320  with sub-notes  316  is generally represented in FIG. 3B as links  338 . According to the present invention, this linking mechanism  338  is bi-directional. Thus, a user viewing portion  322 B of data object  320 A can issue a command to view sub-note  316 C. Also, a user viewing sub-note  316 D can issue a command to automatically launch application  312 B, load data object  320 C, and view portion  322 D. 
     The linking mechanism  338  of the present invention enables users to easily traverse through related data objects  320 , and through sub-notes  316 . For example, a user could command the notes application  302  to display the note  314 A. From note  314 A, the user could move from sub-note  316 A to portion  322 A and back again, from sub-note  316 B to portion  322 B and back again, etc. Accordingly, the notes  314  and sub-notes  316  represent a trail through portions  322  in data objects  320 . 
     The linking mechanism  338  of the present invention enables users to access portions  322  of data objects  320  in any order. This represents random access technology. For example, a user can access in any order the portions  322  of data objects  320  linked to the sub-notes  316  in the note  314 A. In this respect, the invention is superior to conventional mechanisms for linking documents, such as that shown in FIG. 1, where documents must be accessed in a predefined order. Such conventional mechanisms represent sequential or linear access technology. Thus, the trail through documents provided by the linking mechanism  338  of the present invention is much more flexible and user-friendly than the trail provided by conventional linking mechanisms. 
     One or more notes can be grouped together under one note grouping. A note grouping table  390  or other database construct is used to keep track of which notes are in which note groupings. In the example of FIG. 3B, notes  314 A and  314 B are in Note Grouping A. Each note  314  preferably includes information that identifies which Note Grouping it is in, such that it is possible to traverse from a note to a note grouping, and vice versa. This is described further below. Further levels of organization are also supported by the invention, using the same or extensions of the organizational constructs (note groupings, notes, sub-notes, links, etc.) discussed herein. 
     The note/sub-note hierarchy feature and the linking feature of the invention as described above collectively provide at least two ways to organize information, and to memorialize/institutionalize a person or group&#39;s thinking and work product. First, the notes application  302  provides a note/sub-note hierarchy. The note/sub-note hierarchy allows users to group together related sub-notes for organization purposes. That is, related sub-notes may be grouped together under one note. The grouping together of related sub-notes conveys to a certain extent the rationale for the linking together of data objects  320 . 
     Second, the notes application  302  provides a means for explicitly documenting the trail through data objects  320  as established by the linking mechanism  338 . Such documentation is achieved by the sub-notes  316 . As discussed above, each sub-note  316  includes a content field  1512  (FIG. 15) that is used to convey information. The content field  1512  preferably includes at least information that explains the rationale for linking the sub-note  316  to the portion  322  of the data object  320 . Thus, the rationale for the trail established by the linking mechanism  338  is explicitly explained by the information contained in the sub-notes  316 . 
     3.3 Examples of Note/Sub-Note Organization and Linking Sub-Notes To Data Objects 
     The note/sub-note hierarchy feature and the linking feature of the invention shall now be further described in this section by the use of examples. These examples will also serve to illustrate the general operation of the note application  302 . 
     FIG. 5 is a legend  502  of colors  506 ,  510 ,  514 ,  518 ,  522  used by the present invention for color coding purposes. Colors  506 ,  510 ,  514 ,  518 ,  522  are preferably red, green, yellow, blue, and violet, although other colors could alternatively be used. Colors  506 ,  510 ,  514 ,  518 ,  522  could represent different patterns and/or fonts in addition to or instead of colors. This is especially useful when the notes application  302  is used with a computer having a black and white monitor. In one embodiment, the colors/patterns/fonts are user definable (this embodiment is discussed further below). 
     The legend  502  depicts different symbols  508 ,  512 ,  516 ,  520 ,  526  used by the present invention. For purposes of the present invention, symbols  508 ,  512 ,  516 ,  520 , and  524  are associated with colors  506 ,  510 ,  514 ,  518 , and  522 , respectively. When displaying these symbols  508 ,  512 ,  516 ,  520 ,  526 , the invention fills the symbols  508 ,  512 ,  516 ,  520 ,  526  with their associated colors  506 ,  510 ,  514 ,  518 ,  522 , respectively. 
     FIG. 4 depicts an example computer display  402  of the display unit  2826  (FIG.  28 ). The computer display  402  is currently displaying a notes toolbox window  406  and an application window  408 . Also shown. in FIG. 4 is a pointer  420  corresponding to the mouse or other pointing device, such as a trackball. 
     The application window  408  is generated by an application that can process text data objects, such as a word processor or the SMARTPATENT WORKBENCH available from SmartPatents, Inc., Menlo Park, Calif. The application window  408  is currently displaying a portion of a U.S. Patent. 
     The notes toolbox window  406  includes a note menu button  409  and a plurality of pen buttons  410 . In the example of FIG. 4 the notes toolbox window  406  includes five pen buttons  410 , but the notes toolbox window  406  could alternatively include other numbers of pen buttons  410 . 
     A user presses the note menu button  409  to access the note menu  1602  (FIG.  16 ). From the note menu  1602 , the user can access functions provided by the notes application  302  for manipulating notes and sub-notes. These functions include creating a new note and/or sub-note, viewing an existing note and its sub-notes, finding a particular note or sub-note, selecting a view, and modifying privacy settings. The note menu  1602  is discussed in detail below. 
     Each pen button  410  includes an image of a pen, such as pen image  412  in pen button  410 A. The pen images in the pen buttons  410  are color coded using the colors  506 ,  510 ,  514 ,  518 ,  522  shown in FIG.  5 . 
     The pen buttons  410  are used to select portions of data objects that are to be linked with sub-notes of notes. The pen buttons  410  are used as follows. A user selects one of the pen buttons  410  using the mouse. The pointer  420  representing the mouse on the computer display then changes to the image of a pen. The color of the pen is the same as the color of the pen image in the pen button  410  that the user selected. The user then manipulates the pen using the mouse to select a portion of the currently displayed data object (in the case of FIG. 4, a portion of the patent displayed in the application window  408 ). The selected portion of the data object is color coded using the same color as the pen. The notes application  302  creates a new sub-note, and links the sub-note to the selected portion of the data object. 
     Such operation is shown in FIG.  6 . The user selects pen button  410 A, which causes the pointer  402  to change to a pen  620 . The pen  620  is color coded using color  506 , which is the same as the selected pen button  410 A. The user selects text  602 , which is a portion of patent data object displayed in the application window  408 . The notes application  302  instructs the application associated with the application window  408  to color code the selected text  602  using the same color as the pen  620 , i.e., color  506 . 
     The notes application  302  creates a new note, called Note A, and displays Note A in a note window  606 . The note window  606  has a name field  608  in which the name of the note (i.e., Note A) is displayed. The notes application  302  creates a new sub-note, called Sub-note A 1 , and displays Sub-note A 1  in a sub-note window  610 . The notes application  302  links Sub-note A 1  to the selected text  602 . 
     The notes application  302  inserted the new Sub-note A 1  in a new Note A because the computer screen  402  was not displaying an existing note when the text  602  was selected. If, instead, an existing note was being displayed on the computer screen  402  when the text  602  was selected, then the notes application  302  would have inserted the new Sub-note A 1  in that existing note. 
     The notes application  302  displays a linking button  612  adjacent to sub-note window  610 . The linking button  612  is color coded with the same color as the pen  620 , i.e., color  506 . Also, the symbol of the linking button  612  is that which corresponds to this color, i.e., symbol  508 . 
     Similarly, the notes application  302  displays a linking button  604  adjacent to the selected text  602 . The linking button  604  is color coded with the same color as the pen  620 , i.e., color  506 . Also, the symbol of the linking button  604  is that which corresponds to this color, i.e., symbol  508 . 
     Linking button  604  associated with the selected text is used to navigate to and display the sub-note (i.e., Sub-note A 1 ) that is linked to the selected text. For example, assume that the user now closes window  606 . If the user wishes to view the sub-note linked to the selected text  602 , then the user need only click on the linking button  604 . This causes the notes application  302  to display Note A and Sub-note A 1  in the note window  606 . 
     Similarly, linking button  612  associated with Sub-note A 1  is used to navigate to and display the selected text  602  that is linked to Sub-note A 1 . For example, assume that the user now closes window  408 . If the user wishes to view the text linked to Sub-note A 1 , then the user need only click on the linking button  612 . This causes the notes application  302  to launch the application associated with selected text  602 . The notes application  302  then commands the application to load the data object containing the selected text  602 , and further commands the application to scroll within the data object so that the selected text  602  is displayed in the window  408 . 
     Also displayed next to the. sub-note window  610  is an object field  614  and a location field  616 . The object field  614  includes information that describes the object containing the selected text that the corresponding sub-note is linked to. For example, the object field  614  may display: “U.S. Pat. No. 4,444,444.” The location field  616  includes information that describes the location of the selected text in the object. For example, the location field  616  may display: “Column 3, line 25.” 
     FIG. 7 continues the scenario of FIG.  6 . In FIG. 7, the user selects pen button  410 B, causing the pointer to change to pen  720 . The user selects text  702  using pen  720 . The notes application  302  creates a new sub-note, called Sub-note A 2 . Note that this Sub-note A 2  is added to existing Note A, because Note A was being displayed when the user selected text  702 . Also note that selected text  602  overlaps with selected text  702 . The present invention allows portions in a data object that are to be linked with sub-notes to be distinct, to partially overlap, or to completely overlap. Such functionality of the invention enables users to precisely associate sub-notes with portions in data objects. 
     Sub-notes in a note can be linked to portions of data objects associated with different applications. This is the scenario shown in FIG.  8 . Recall that Note A has Sub-notes A 1  and A 2  that are linked to portions  602 ,  702  in a patent data object. The patent data object is associated with a word processing application, for example. In FIG. 8, the user launched a spread sheet application. A spreadsheet  804  is displayed in a window  802 . The user selected pen button  410 D and then pen button  410 C. The user used the resulting pens to select portion  806  (including one cell) and then portion  808  (including four cells) of the spreadsheet  804 . In response to such action by the user, the notes application  302  created a new sub-note, Sub-note A 3 , and linked Sub-note A 3  to selected portion  806 . The notes application  302  then created a new sub-note, Sub-note A 4 , and linked Sub-note A 4  to selected portion  808 . 
     FIG. 9 continues the scenario of FIG.  8 . The user closed window  606  (containing Note A). The user then selected pen button  410 C, resulting in pen  920 . The user selected portion  902  of the spreadsheet  804  using pen  920 . The notes application  302  created a new sub-note, Sub-note B 1 , and linked Sub-note B 1  to selected portion  902 . Since no note was being displayed when the user selected portion  902 , the notes application  302  created a new note, Note B, and inserted the Sub-note B 1  into Note B. 
     FIG. 10 illustrates a scenario where the notes application  302  is being used with a database application. In FIG. 10, the user has used pen  1020  to select portion  1006 , representing a field in two records of a database  1002 . The notes application  302  created Sub-note B 2  in Note B, and linked Sub-note B 2  to portion  1006 . 
     FIG. 11 illustrates a scenario where the notes application  302  is being used with a personal finance application. A check register  1102  is displayed in a window  1104 . The user used a pen  1120  to select a portion  1106  of the check register  1102 . This portion  1106  corresponds to check number  532 . The notes application  302  created a new Sub-note B 3 , and linked Sub-note B 3  to the selected portion  1106 . 
     FIG. 12 illustrates a scenario where the notes application  302  is being used with an audio processor. The audio processor displays a window  1202  that includes a title field  1206  and a track field  1208  for displaying the title and track of the audio work that is being processed. The window  1202  includes controls  1212  for manipulating the audio work, and a window  1214  that graphically characterizes the audio work over time. In the scenario of FIG. 12, the user selected pen button  410 B and used the resulting pen to select track  5  (by clicking on “5” displayed in the track field  1208 , for example). The notes application  302  created new Sub-note B 4 , and linked Sub-note B 4  to track  5 . Then, the user selected pen button  410 A and used the resulting pen  1250  to select a portion  1216  of the audio work. The notes application  302  created new sub-note B 5 , and linked Sub-note B 5  to this portion  1216  of the audio work. 
     The example of FIG. 12 illustrates an important feature of the invention. The invention can be used to select portions of text based data objects, such as text documents, computer programs, spread sheets, database files, etc. The invention can also be used to select portions of non-text based data objects, such as audio data objects (as in FIG.  12 ), video data objects, graphics data objects, etc. Thus, the invention can be used to mark or “bookmark” text based and non-text based data objects for fast reference and retrieval. 
     As noted above, a sub-note can be linked to a portion of a note. This scenario is depicted in FIG.  13 . The user selected patent button  410 A. The user then used the resulting pen  1350  to select a portion  1302  of Note B. This portion  1302  includes Sub-note B 2  and Sub-note B 3 . The notes application  302  created a new Sub-note C 1 , and linked Sub-note C 1  to portion  1302  of Note B. Linking button  1316  in Note B links portion  1302  to Sub-note C 1 . Similarly, linking button  1310  in Note C links Sub-note C 1  to portion  1302  of Note B. The notes application  302  created a new Note C and inserted Sub-note C 1  into Note C because no other note was displayed when the portion  1302  was selected (other than Note B; however, preferably, a note cannot contain a sub-note that is linked to a portion of itself; accordingly, the notes application  302  created Note C to contain Sub-note C 1 ). 
     As will be apparent from the foregoing, the notes application  302  can operate with any application that supports the interface  310  (FIG.  3 A). The interface  310  preferably uses the OLE standard. The number of applications which support the OLE standard is rapidly growing. Accordingly, the number of applications which are operable with the notes application  302  is increasing. It should be understood, however, that the notes application  302  is not limited to use with the OLE standard. The notes application  302  can be used with any standard that allows one software application to interact with another.) 
     3.4 Viewing Notes, Sub-Notes, and Data Objects 
     The present invention supports a number of modes for displaying the contents of the notes database  308 . These modes are called views. The invention supports a note centric view (also called a note view), an object centric view (also called an object view), a link centric view (also called a link view), and a user-defined view. A user can elect to print the notes database  308  while in any of these views, such that the print out has the same appearance to that which is displayed on the computer display. 
     Users can select any of these views to display the contents of the notes database  308 . Users can also alternate between these views. Further, users can simultaneously display multiple views of the notes database  308 . This is shown in FIG. 43, for example, where the user has elected to display the note view in a window  4304 , the link view in the a window  4306 , the object view in a window  4308 , and the user-defined view  4310 . By utilizing multiple windows, such as windows  4304 ,  4306 ,  4308 ,  4310 , the user can simultaneously display different views of the same or different portions of the notes database  308 . 
     The ability to display information using different views, to switch between views, and/or to simultaneously display different views of the same or different information is useful for enabling users to fully comprehend and best manipulate the information. In essence, the invention allows users to view and perceive information in the notes database  308  from different angles and perspectives. Depending on the nature of the information or task, some views may be more appropriate than others. The invention provides users with the ability to customize the display based on the needs of the moment. Such flexibility facilitates comprehension and manipulation of information. 
     The note view, object view, link view, and user-defined view are described in the following sections. 
     3.4.1 Note View 
     There are two note views: the standard note view and the modified note view. 
     The standard note view is shown in FIGS. 6-13. The standard note view includes at least one note window having a note and its sub-notes displayed therein. This is shown in FIG. 6, for example, where the note window  606  has displayed therein Note A and its Sub-note A 1 . The standard note view may or may not also include one or more application windows each displaying a portion of an object that is linked to one of the sub-notes displayed in the note window. In FIG. 6, for example, the application window  408  is displayed. The application window  408  has displayed therein a portion  602  of a patent document that is linked to Sub-note A 1  in the note window  606 . The link between data object portion  602  in the application window  408  and Sub-note A 1  is indicated by the linking buttons  604 ,  612  that have the same shape and color. 
     The modified note view illustrates a note and its sub-notes, and all data objects linked to the sub-notes. An example modified note view is shown in FIG.  30 . The modified note view displays, in a window  3002 , a note window  3004  that is currently displaying Note A and its Sub-notes A, B, and C. The modified note view also displays the data object portions linked to the sub-notes (i.e., Sub-notes A, B, C) displayed in the note window  3004 . These data object portions are displayed in application windows  3018 ,  3020 ,  3022 . 
     Note A may include additional sub-notes that are not currently displayed in the note window  3004  (due to space limitations in the note window  3004 ). These additional sub-notes can be displayed by using well known window navigation tools, such as the window scroll bars. When such additional sub-notes are scrolled into view in the note window  3004 , additional application windows having displayed therein the data object portions linked to the sub-notes are also scrolled into view in the window  3002 . 
     The modified note view also displays bidirectional arrows  3012 ,  3014 ,  3016  that indicate the links between sub-notes and data object portions. These arrows  3012 , 3014 ,  3016  are “live,” in that users can select and manipulate these arrows in order to modify the note/sub-note hierarchy. For example, a user can delete a link between a sub-note and a data object portion by selecting and deleting the corresponding arrow in the modified note view. A user can also modify the linkage between sub-notes and data object portions by selecting and then dragging an arrow from one sub-note to another sub-note, and or from one data object portion to another data object portion. 
     Users can also select and manipulate the arrows  3012 ,  3014 ,  3016  in order to modify the attributes of the underlying links. Such attributes relate to privacy, security, and priority. The manipulation of the arrows  3012 ,  3014 ,  3016  is described further in a section below. 
     For readability purposes, details of the note window  3004  and the application windows  3018 ,  3020 ,  3022  are not shown in FIG.  30 . Preferably, however, the note window  3004  and the application windows  3018 ,  3020 ,  3022  include the same features as those shown in FIGS. 6-13. For example, the application windows display linking buttons (if any) that are not related to the sub-notes in Note A. If a user presses one of these linking buttons, then the note corresponding to this linking button is retrieved and displayed using the standard note view, which is the default view (users may select a different default view). 
     3.4.2 Object View 
     The object view displays a data object and all sub-notes linked to the data object. An example object view is shown in FIG. 31. A data object  3101  is being displayed in an application window  3104 . Only a part of the data object  3101  is being displayed due to the size limitations of the application window  3104 . 
     Sub-notes linked to the data object  3101  are also being displayed. These sub-notes are displayed in note windows  3122 ,  3124 ,  3126 ,  3128 . Only those sub-notes linked to data object portions currently being displayed in the application window  3104  are displayed. 
     Other parts of the data object  3101  may be displayed in the application window  3104  by using well known window navigation tools, such as the window scroll bar. As other parts of the data object  3101  are scrolled into view in the application window  3104 , any sub-notes linked to these newly displayed parts of the data object  3101  are also scrolled into view in the window  3102 . 
     The object view also displays bidirectional arrows  3114 ,  3116 ,  3118 ,  3120  that indicate the links between sub-notes and data object portions. As discussed above (and further discussed below), these arrows  3114 ,  3116 ,  3118 ,  3120  are “live,” in that users can select and manipulate these arrows in order to modify the note/sub-note hierarchy, and to modify the attributes associated with the underlying links. 
     For readability purposes, details of the note windows  3122 ,  3124 ,  3126 ,  3128  and the application window  3104  are not shown in FIG.  31 . Preferably, however, the note windows  3122 ,  3124 ,  3126 ,  3128  and the application window  3104  include the same features as those shown in FIGS. 6-13. For example, the note windows  3122 ,  3124 ,  3126 ,  3128  may include sub-notes and linking buttons that are not related to the data object  3101  in application window  3104 . If a user presses one of these linking buttons, then the data object portion corresponding to this linking button is retrieved and displayed using the standard note view, which is the default view. 
     3.4.3 Link View 
     The link view displays the connections between note groupings, notes, and sub-notes, and the links between sub-notes and data object portions. The link view is useful for obtaining a high level display of the note grouping/note/sub-note hierarchy, and sub-note/data object portion linkage. The link view is also useful for editing and replicating the note grouping/note/sub-note hierarchy (this is described further in a section below). 
     An example link view is shown in FIG.  29 . The link view displays the title (or identifier) of note groupings, notes, sub-notes, and objects. For example, Sub-note A is represented by its name, “Sub-note A,” displayed in an oval. Data object A is represented by its name, “Data Object A,” displayed in an oval (this oval may also include information that identifies the portion of Data Object A that is linked to the corresponding sub-note(s)). The contents of these note groupings, notes, sub-notes, and objects are not shown in the link view. 
     A user may view the contents of a note grouping, a note, a sub-note, and/or an object by selecting the corresponding icon in the link view. For example, a user can display the contents of Note A by clicking on icon  2906 . This results in displaying Note A using the default standard note view. 
     The link view also displays the connections between note groupings, notes, and sub-notes by using connector lines  2950 . The link view further displays the links between sub-notes and data object portions by using bidirectional arrows  2911 ,  2917 . As discussed above (and further discussed below), these connector lines  2950  and arrows  2911 ,  2917  are “live,” in that users can select and manipulate these connector lines/arrows in order to modify the note grouping/note/sub-note hierarchy, and to modify the attributes associated with the underlying connections/links. 
     Other portions of the note grouping/note/sub-note hierarchy can be viewed by using well known window navigation tools, such as the window scroll bars. 
     3.4.4 User-Defined View 
     The user-defined view displays note groupings, notes, sub-notes, and/or data objects that satisfy search criteria entered by the user. 
     An example user-defined view is shown in FIG.  32 . This view is called the icon view. In this example, the user has elected to view all sub-notes and linked data objects that are tagged with a particular icon (this icon is shown in window  3204 ). (A sub-note or data object portion is tagged with a particular icon by using the appropriate pen when selecting the data object portion and creating the sub-note. The invention also allows users to modify these tags.) In this example, Sub-notes B and C of Note A, Sub-note E of Note C, and Sub-note E of Note D were tagged with the user selected icon. Thus, these notes and sub-notes are displayed in window  3202 . The data object portions that are linked to these sub-notes also are tagged with the user selected icon. Thus, these data object portions are also displayed. The links between the sub-notes and the data object portions are indicated by the bidirectional arrows  3212 ,  3214 ,  3218 , which are also displayed. As discussed above (and further discussed below), these arrows  3212 ,  3214 ,  3216 ,  3218  are “live,” in that users can select and manipulate these arrows in order to modify the note/sub-note hierarchy, and to modify the attributes associated with the underlying links. 
     For readibility purposes, details of the note windows  3206 ,  3208 ,  3210  and the application windows  3220 ,  3222 ,  3224  are not shown in FIG.  32 . Preferably, however, the note windows  3206 ,  3208 ,  3210  and the application windows  3220 ,  3222 ,  3224  include the same features as those shown in FIGS. 6-13. For example, the note windows  3206 ,  3208 ,  3210  may include sub-notes and linking buttons that are not related to the data objects displayed in the application windows  3220 ,  3222 ,  3224 . If a user presses one of these linking buttons, then the data object portion corresponding to this linking button is retrieved and displayed using the standard note view, which is the default view. 
     3.5 Editing Note/Sub-Note Organization 
     The invention includes many flexible features and functions for modifying and replicating the note grouping/note/sub-note hierarchy. These are described below. 
     3.5.1 Modification 
     The invention enables users to modify the note grouping/note/sub-note hierarchy. In other words, the invention enables users to switch or copy notes from one note grouping to another, or switch or copy sub-notes from one note to another. 
     The invention provides a number of ways for the user to modify this hierarchy. One way involves modifying the connector lines that appear in a link view. Consider the example of FIG. 29. A user can delete Sub-note C from Note B, and add Sub-note D to Note B, by selecting and dragging connector line  2950 A so that it points to Sub-note D, instead of Sub-note C. This is shown as connector line  2950 B. A user can move Sub-note F from Note D to Note C by selecting and dragging connector line  2950 C so that it points at Note C, instead of Note D. This is shown as connector line  2950 D. 
     Users can remove notes from note groupings, or sub-notes from notes, by selecting and deleting the corresponding connector lines. For example, a user can remove Note B from Note Grouping B by selecting and deleting connector line  2950 E. 
     Users can add a note to a note grouping, or add a sub-note to a note, by creating a new connector line. For example, a user can add Note C to Note Grouping A by creating and appropriately positioning connector line  2950 F. 
     The creation, deletion, or modification of a connector line does not affect any other connector lines. Consider the above example where Sub-note C is removed from Note B, and Sub-note D is added to Note B. This was done by moving connector line  2950 A so that its appears as connector line  2950 B. This modification does not affect connector line  2950 G. Thus, Sub-note C remains in Note A. 
     The invention also enables users to modify the links between sub-notes and data object portions. The invention provides a number of ways for the user to perform such modifications. One way involves modifying the bidirectional arrows (such as arrows  2911  and  2917  in FIG. 29) that appear in a link view. Such manipulation of the bidirectional arrows is similar to the manipulation of connector lines, described above. 
     The invention provides other interfaces for performing the modifications discussed above. Essentially, users can perform such modifications while in any view. Consider the user-defined icon view shown in FIG. 32. A user can move sub-notes from one note to another by using well known copy/cut and paste operations. Also, a user can change the linkage between sub-notes and data object portions by clicking and dragging the bidirectional arrows  3212 ,  3214 ,  3216 , and  3218 . 
     3.5.2 Replication 
     A great deal of time and effort may go into the creation of a note grouping/note/sub-note hierarchical database. Typically, a database is specific to a particular task or project. However, it is often the case that parts of a database are applicable to another task or project. For efficiency purposes, users would like to reuse a database generated for one project to the extent possible in another project. The invention provides powerful tools for enabling a user to identify and replicate portions of an existing database that may be relevant to another project. These replicated portions constitute the foundation of a new hierarchical database. 
     In some cases, a user may already know which parts of a database are pertinent to another project. In such cases, the user may select those parts and replicate (copy) them to a new database. Consider the link view shown in FIG.  29 . In this example, the user knows that a portion of Note Group B is relevant to a new project. Accordingly, the user has selected this portion of Note Group B. This selection is indicated by dashed lines  2942 . The user then commands the note application  302  to replicate this portion of Note Group B, and to form a new database using this replicated portion. 
     In other cases, the user does not know which parts of a database are pertinent to another project. In these cases, the user can use the invention&#39;s searching capabilities to identify note groupings, notes, sub-notes, and/or data object portions that are relevant to this other project. The user can then replicate these identified note groupings, notes, sub-notes, and data object portions to a new database. FIG. 33 illustrates a new database that was created based on a search conducted on the example database of FIG.  29 . The invention supports searching based on key words, date/time of creation/modification, creator, icon tags, etc. The searching capabilities of the invention are discussed below. 
     3.6 User Interface 
     As discussed above, the notes application  302  includes a user interface  304 . Referring to FIG. 34, the user interface  304  enables a user  3404  to interact with the notes database  308  and source material  3410 , representing data objects. The user  3404  interacts with the user interface  304  so as to create note groupings, notes, and sub-notes, establish and modify the note grouping/note/sub-note hierarchy, establish and modify the links between sub-notes and data object portions, and in all other ways interact with the notes database  308  and the source material  3410 . 
     It is very important that the user interface  304  provide the user  3404  with an easy to use (i.e., user friendly) interface to the notes database  308 , the source material  3410 , and to the features and functions provided by the notes application  302 . If the user interface  304  is user friendly, then the user  3404  is more likely to utilize the notes application  302  to document his thinking and work product. 
     The user interface  304  may be implemented using any user interface tools, approaches, techniques, technology and/or applications that currently exist, or that will be developed in the future. In one embodiment, the user interface  304  is implemented as a computer based graphical user interface (GUI). Example screen shots from this GUI are shown in FIGS. 4,  6 - 13 ,  29 - 33 , and  43 . 
     In another embodiment, the user interface  304  is implemented in whole or in part using virtual reality (VR) technology. Significant VR technology has been developed, and more is currently being developed. Virtual reality is discussed in many publicly available documents, such as  Virtual Reality Applications and Explorations,  edited by Alan Wexelblat, Academic Press, Cambridge, Mass., 1993, and  On the Cutting Edge of Technology,  Sams Publishing, Carmel, Ind., 1993 which are incorporated herein by reference in their entireties. 
     It should be understood, however, that the invention is adapted and intended to operate with other user interface technology that currently exists, or that will be developed in the future. 
     FIG. 35 represents an example VR scenario  3502  according to a preferred embodiment of the invention. The user is represented in VR scenario  3502  by a hand  3504 . As will be appreciated by persons skilled in the VR arts, the user selects and manipulates objects in the VR world of FIG. 35 by using the virtual hand  3504 , just like the user selects and manipulates objects in the real world using his own hand. Other techniques for manipulating objects in the VR world will be apparent to persons skilled in the VR arts. For example, manipulation may be accomplished by voice command, or by thought (tied to brain waves or brain impulses), or by body gestures, etc. 
     In the example of FIG. 35, the user selects a book  3508  from a library  3506 . The user opens the book  3508  until a passage  3510  of interest is found. The user selects this passage  3510  and then links this passage  3510  to a sub-note  3518  in Note A. Such linkage may automatically occur upon the selection of the passage  3510  (since such selection results in the creation of sub-note  3518 , and in the creation of the link between sub-note  3518  and the passage  3510 , as described above). Alternatively, the user can link passage  3510  with sub-note  3518  by moving the hand  3504  from the passage  3510  to the sub-note  3518 . 
     The user can enter comments into the sub-note  3518  using any input mechanism or procedure, such as typing on a real or virtual keyboard, audibly dictating the comments, etc. 
     Any of the displays and screen shots discussed herein, such as those shown in FIGS. 4,  6 - 13 ,  29 - 33 , and  43 , can be displayed and manipulated in the VR world. The user can manipulate the items and objects in those displays via the VR hand  3504  or any other virtual construct, instead of or in addition to a computer (physical or virtual) keyboard and mouse. The combination of the notes application  302  with virtual reality creates a very powerful, user friendly application. 
     In the discussion herein, the user is often said to issue a command, press a button, select an option from a menu, review a computer display, input/key in information or commands, or perform some other type of action that requires interaction with the computer. It should be understood that, according to the present invention, such interaction can be achieved using any type of user interface, including a conventional computer interface (using a keyboard and mouse, for example), or a virtual reality interface, as just described above. 
     3.7 Security 
     The invention includes many functions, features, and capabilities to maintain the security of the information contained in the note database  308 . These security features can generally be categorized as follows: (1) security on individual note groupings, notes, sub-notes, links, and objects; and (2) security of the note database  308  as a whole. These two security features are discussed below. 
     3.7.1 Security on Individual Note Groupings, Notes, Sub-notes, Links, and Data Objects 
     A person, group, or organization may wish to limit access to note groupings, notes, sub-notes, links, and/or data objects. Only people or groups who satisfy some specified criteria would have access to such note groupings, notes, sub-notes, links, and/or data objects. The present invention supports features for securing individual note groupings, notes, sub-notes, links, and data objects. 
     A note grouping, note, sub-note, link, or data object may be secured based on a number of criteria, including creator, owner, password, security level, or any other well known security criteria. For example, if a sub-note is secured based on the creator criteria, then only the creator may access the sub-note. If a sub-note is secured based on password, then only persons who have the correct password may access the sub-note. If a sub-note is secured based on security level, then only persons having the appropriate security level will have access to the sub-note. 
     In one embodiment, a person or group who satisfies the current security criteria for a note grouping, note, sub-note, link, or data object may modify the security criteria for the note grouping, note, sub-note, link, or data object. In other embodiments, only persons or groups who have satisfy a specified, alternate security criteria (such as administrators) may change existing security criteria. 
     If a note grouping is secured, then only persons who satisfy the specified criteria may gain access to the note grouping, and the notes, sub-notes, and connectors/links contained in the note grouping. 
     If a note is secured, then only persons who satisfy the specified criteria may gain access to the note, and the sub-notes and connectors/links contained in the note. 
     If a sub-note is secured, then only persons who satisfy the specified criteria may gain access to the sub-note, and the link contained in the note. 
     If a link (that links a sub-note to a data object portion) or a connector (that establishes the note grouping/note/sub-note hierarchy) is secured, then only persons who satisfy the specified criteria may gain access to and traverse the link/connector. 
     This effect of security is illustrated in the example of FIG.  44 . Note A is displayed in a note window  4406 . It is assumed that Note A is not secured, or that the current user satisfies the security criteria associated with Note A. Note A includes Sub-notes A, B, and C. It is assumed that Sub-notes A and B are not secured, or that the current user satisfies the security criteria respectively associated with Sub-notes A and B. Accordingly, Sub-notes A and B are displayed. Sub-note C is secured. However, the current user does not satisfy the security criteria of Sub-note C. Thus, Sub-note C is not displayed. 
     It is assumed that the current user satisfies the security criteria respectively associated with link  4414 . Thus, the link  4414  is active. The current user may manipulate and traverse link  4414 . Thus, the data object associated with link  4414  is displayed in application window  4420 . The current user does not satisfy the security criteria of link  4416 . Thus, link  4416  is inactive. The current user may not manipulate and traverse link  4416 . Thus, the data object associated with link  4416  is not displayed. It is irrelevant whether the current user does or does not satisfy the security criteria of link  4418 . In either case, link  4418  is inactive since its Sub-note C is inactive (in other embodiments, the security state of a link is separate and distinct from the security state of its sub-note). 
     3.7.2 Security on the Note Database as a Whole 
     According to some embodiments of the present invention, the notes database  308  is stored in a single computer. In other embodiments of the present invention, the notes database  308  is distributed among multiple databases. Procedures and technology for distributing the notes database  308 , and for working with the distributed notes database  308 , will be apparent to persons skilled in the relevant art(s). 
     In some circumstances, the distribution of the notes database  308  is advantageous for implementation, performance, and robustness reasons. The motivations and advantages of distributed database systems in this regard are well known. 
     According to the present invention, the notes database  308  is also distributed for security reasons. In some situations, it is necessary to maintain the confidentiality and secrecy of the notes database  308 . Distributing the notes database  308  aids in this effort, and it ensures that the inadvertent or improper disclosure of one part of the notes database  308  maintained at one site does not result in the disclosure of the other parts of the notes database  308  at other sites. 
     In some cases, it is critical that the linkage information contained in the notes database  308  be kept secret. The present invention utilizes techniques in addition to the data distribution approached described above to secure the linkage information in the notes database  308 . These additional techniques also relate to data distribution. 
     In particular, the present invention preferably partitions the notes database  308  into a note information database  3406  and a note/object linking information database  3408 . The note/object linking information database  3408  contains the linkage information that specifies how sub-notes are linked to data object portions. The note information database  3406  includes all information about notes and sub-notes except for the linkage information. 
     The note information database  3406  is distributed among a first set of sites. The note/object linking information database  3408  is distributed among a second set of sites. The first and second sets of sites may be the same, may be completely different, or may be partially the same. 
     FIG. 38 illustrates an example implementation of the invention. In this example, the note information database  3406  is distributed among sites  3804  and  3406 . The note/object linking information database  3408  is distributed among sites  3806 ,  3810 , and  3812 . These sites are connected via a network  3820 , which may represent any type of communication medium in any form or configuration, such as a public network (the Internet, for example), a private network (such as a virtual network), dial up telephone lines, etc. The communication medium can include any type of communication links, such as fiber optics, coaxial cable, wireless, satellite links, etc., or any combination of these. 
     The invention uses other techniques for securing the notes database  308 . In some embodiments, for example, all or part of the notes database  308  is encrypted. For example, references contained in the note information database  3406  to the note/object linking information database  3408  are encrypted using any well known encryption mechanism or algorithm, such as key encryption. Encryption of the notes database  308  is further described below. 
     3.8 Search Capabilities 
     The invention supports powerful search features for identifying note groupings, notes, sub-notes, links, and/or data objects that satisfy user supplied search criteria. Users can perform key word searches, searches based on date/time of creation or modification, searches based on icon tagging (icons can be predefined or user defined), searches based on creator or owner, searches based on security/privacy levels, etc. Preferably, sub-notes are indexed and searchable. Also, fields (predefined or user defined) within note groupings, notes, and sub-notes are indexed and searchable. 
     The user can limit the search to a user-defined path through the note/sub-note hierarchy (for example, the user can limit the search to a path that starts with a user specified note grouping, note, sub-note, link, etc.). 
     The operation of the search capabilities of the present invention are described further below. 
     4. Notes Database 
     Implementation of the notes database  308  according to an embodiment of the present invention shall now be described with reference to FIG.  14 . FIG. 14 illustrates an example notes database  308  that stores Notes A, B, and C. Notes A, B, and C correspond to the example shown in FIGS. 8,  12 , and  13 , respectively. 
     The notes database  308  includes a node or record for each note. These nodes are called note nodes. Accordingly, the notes database  308  includes note nodes  1404 ,  1406 , and  1408  for Notes A, B, and C. The note nodes  1404 ,  1406 , and  1408  are arranged in a linked list  1450  that begins with a root node  1402  and ends with a null node  1410  (or a null pointer). Procedures for establishing, traversing, modifying, and maintaining linked lists are well known to persons skilled in the relevant art(s). 
     Each note node, such as note node  1404 , includes a note identifier field  1412 , a next note field  1414 , and a next sub-note field  1418 . The note identifier field  1412  stores information that identifies the note, such as “Note A” for note node  1404 . The next note field  1414  stores either (1) a pointer to the next note node in the note linked list  1450 , or (2) a null pointer if the note node is the last note node in the note linked list  1450  (see the note node  1408  for Note C). The next sub-note field  1418  stores either (1) a pointer to a sub-note linked list corresponding to sub-notes in the note, if the note has one or more sub-notes, or (2) a null pointer if the note does not have any sub-notes. 
     Each note node may include additional information, such as information that identifies the privacy/security criteria associated with the note. 
     The notes database  308  includes a node or record  1422  for each sub-note. These nodes  1422  are called sub-note nodes. The sub-note nodes  1422  for a note&#39;s sub-notes are arranged in a linked list, called a sub-note linked list. Consider sub-note linked list  1452 , corresponding to Node A&#39;s sub-notes. The sub-note linked list  1452  begins with Node A&#39;s note node  1404  and ends with a null node  1432  (or a null pointer). 
     Each sub-note node, such as sub-note node  1422 A, includes a sub-note name field  1424 , a descriptor field  1426 , a next sub-note field  1428 , and a parent field  1429  (for readibility purposes, the parent field  1429  is only shown in sub-note node  1422 A, but it exists and operates in the same manner for all sub-note nodes  1422 ). The sub-note name field  1424  stores the name of the sub-note, such as “Sub-note A.” The next sub-note field  1428  stores either (1) a pointer to the next sub-note node in the sub-note linked list  1452 , or (2) a null pointer if the sub-note node is the last sub-note node in the sub-note linked list  1452  (see the sub-note node  1422 D for Sub-note A 4 ). The parent field  1429  stores an address or pointer that points back to the note in which the sub-note is contained. Thus, for the sub-note node  1422 A, the parent field  1429  includes a pointer to note node  1404 . 
     The descriptor field  1426  stores information pertaining to the sub-note. FIG. 15 is a block diagram of an exemplary descriptor field  1426 . The descriptor field  1426  includes a note identifier field  1503 , a sub-note identifier field  1504 , an object identifier field  1506 , a location identifier field  1508 , a range field  1509 , a pen field  1510 , a contents field  1512 , a sub-note privacy settings field  1514 , and a link privacy settings field  1516 . In some implementations, some of these fields are unused. 
     The note identifier field  1503  includes information that identifies the note in which the sub-note is contained. 
     The sub-note identifier field  1504  includes information that uniquely identifies the sub-note. For example, this identifier could be composed of the name of the note concatenated with the date/time stamp of when the sub-note was created. Other procedures for generating the sub-note identifier could alternatively be used, such as a hashing procedure. 
     The sub-note object identifier field  1506  stores information that identifies the data object containing the selected portion to which the sub-note is linked. This field  1506  may also store information that identifies the application associated with the data object. 
     The location identifier field  1508  stores information that identifies the location of the selected portion in the data object. If the data object is a patent, for example, the location identifier field  1508  may store “Column 5, line 15” or the like. 
     The range field  1509  stores information that identifies or indicates the range of the selected portion in the data object. If the data object is a patent, for example, the range field  1509  may store “Column 7, line 23.” The location identifier field  1508  in combination with the range field  1509  identifies the selected portion in the data object. In the above example of a patent document, the selected portion goes from Column 5, line 15 to Column 7, line 23. 
     The pen field  1510  stores information that identifies the pen that was used to select the selected portion to which the sub-note is linked. 
     The contents field  1512  stores the information that the user entered into the sub-note window, such as sub-note window  610  shown in FIG.  8 . The contents field  1512  may include information of any form. For example, the contents field  1512  may store text data, image data, digitized audio and/or video, an executable computer program, tactile data (for controlling a braille device, for example), and/or links or references to any of the above. 
     The sub-note privacy settings field  1514  stores the privacy/security criteria associated with the sub-note. 
     The link privacy settings field  1516  stores the privacy/security criteria associated with the link of the sub-note. 
     Each note node and/or sub-note node may store additional information, such as the security/privacy criteria associated with the connector lines that connect notes to sub-notes. 
     The notes database  308  also includes a note grouping table  390  (FIG. 45) or some other functionally equivalent data structure. The note grouping table  390  indicates the notes contained in each note grouping. 
     The notes database  308  could be implemented in ways other than that shown in FIG. 14, and described above. In particular, the notes database  308  could be implemented using any well known data structure or organization. Various data structures are described in many publicly available documents, such as Niklaus Wirth,  Algorithns+Data Structures=Programs,  Prentice Hall, 1976, which is herein incorporated by reference in its entirety. 
     As discussed above, in some embodiments the notes database  308  is partitioned into a note information database  3406  and a note/object linking information database  3408 . The note information database  3406  and the note/object linking information database  3408  may be distributed among a plurality of sites, as shown in FIG.  38 . 
     FIG. 37 illustrates the note information database  3406  and the note/object linking information database  3408  in greater detail. In essence, the descriptor field  1426  from each sub-note node  1422  is divided among the note information database  3406  and the note/object linking information database  3408 . The note information database  3406  stores the note identifier  1503 , the sub-note identifier  1504 , the pen  1510 , the contents  1512 , and the sub-note privacy settings  1514 . The note/object linking information database  3408  stores the object identifier  1506 , the location identifier  1508 , the range  1509 , and the link privacy settings  1516 . Other information stored in the note nodes and the sub-note nodes are preferably stored in the note information database  3406 . 
     The note information database  3406  also stores for each sub-note node a link address field  3702 . Similarly, the note/object linking information database  3408  stores for each sub-note node a link address field  3706 . An entry in the note information database  3406  corresponds to an entry in the note/object linking information database  3408  if the contents of the link address fields  3702 ,  3706  are the same. 
     The use of the note information database  3406  and the note/object linking information database  3408  shall now be described. Suppose that the notes application  302  is processing a sub-note and the data object portion that it is linked to. The notes application  302  retrieves the entry in the note information database  3406  corresponding to this sub-note. The notes application  302  processes the information contained in the note identifier field  1503 , the sub-note identifier field  1504 , the pen field  1510 , the contents field  1512 , and the sub-note privacy settings field  1514  in whatever way appropriate for the type of processing that the notes application  302  is performing. 
     In order to identify and access the linked data object portion, the notes application  302  retrieves the link address from the link address field  3702 . This link address is used as an index into the note/object linking information database  3408  to identify the entry corresponding to the entry being processed in the note information database  3406 . The linked data object is identified by the information in the object identifier field  1506 , location identifier field  1508 , and range field  1509  of this corresponding entry. 
     In some embodiments, the invention further secures the information in the notes database  308  by encrypting the link address in the link address field  3702  of the note information database  3406 , and by encrypting the object identifier field  1506 , location identifier field  1508 , and range field  1509  in the note/object linking information database  3408 . In these embodiments, the notes application  302  retrieves the link address from the link address field  3702 . The notes application  302  then decrypts this link address (indicated by  3704 ). This decrypted link address is used as an index into the note/object linking information database  3408  to identify the entry corresponding to the entry being processed in the note information database  3406 . The linked data object is identified by the information in the object identifier field  1506 , location identifier field  1508 , and range field  1509  of this corresponding entry. Before it can use this information, however, the notes application  302  must decrypt the object identifier field  1506 , location identifier field  1508 , and range field  1509  (indicated by  3708 ). This decrypted information can then be used to identify linked portion  3712  in data object  3710 . 
     In the description contained herein, it is often said that information is stored or retrieved from the notes database  302 . More generally, it is said that the notes database  302  is accessed. The technology, procedure, algorithms, etc., for accessing the notes database  302  (whether the notes database  302  is centralized or distributed) will be apparent to persons skilled in the relevant art(s). 
     5. Operation of the Invention 
     The operation of the present invention shall now be described with reference to a flowchart  1702  shown in FIG.  17 . Flowchart  1702  illustrates the manner in which a user interacts with the notes application  302  to organize data objects, and to manipulate notes attached to portions of data objects. 
     Such user interaction with the notes application  302  is preferably achieved through interaction with a user interface  304  that forms part of the notes application  302 . As apparent from the discussion below, the user interface  304  of the present invention is very powerful and flexible. In particular, the user interface  304  allows users to access the functionality of the notes application  302  in any number of ways. Accordingly, the operational steps shown in flowchart  1702  and in other flowcharts discussed below represent one way (i.e., one operational sequence) of accessing the functions provided by the notes application  302 . Users may access and traverse the functions provided by the notes application  302  in any number of other ways via interaction with the menus provided by the user interface  304 . Such other ways (i.e., such other operational sequences) will be apparent to persons skilled in the relevant art(s). 
     In step  1704 , the user issues a command to an operating system executing in the computer system  2802 . The user may issue this command via a keyboard or a well known point-and-click approach, or via a body gesture, thought, or voice command when using a VR user interface, or via any other well known means for entering a command. 
     If the user issued a command to launch an application, then control line  1710  is taken. If the user issued a command to create a new note/sub-note, and this command was issued using the note menu  1602 , then control line  1712  is taken. If the user issued a command to create a new note/sub-note, and this command was issued using a pen (such as pen  1350  in FIG. 13) or VR hand  3504  or the like, then control line  1714  is taken. If the user issued a command to view a note, and this command was issued by selecting a linking button in a data object, then control line  1716  is taken. If the user issued a command to view a note, and this command was issued from the note menu, then control line  1718  is taken. If the user issued a command to select a view, then control line  1719  is taken. If the user issued a command to find a note, then control line  1720  is taken. If the user issued a command to modify the privacy/security settings associated with a note grouping, note, sub-note, or link, then control line  1721  is taken. If the user issued a command to edit one or more notes, then control line  1722  is taken. These control flows and commands are discussed below. 
     5.1 Launch an Application 
     If the user in step  1704  issued a command to launch an application, then step  1706  is performed. 
     In step  1706 , the operating system in the computer system  2802  invokes the user-specified application in a well known manner. The application may be a word processing application, a spread sheet application, a database application, a communication application, a video/audio processing application, a financial application, etc. The invoked application displays an application window, such as application windows  408 ,  802 ,  1004 ,  1104 , and  1202  shown in FIGS.  4  and  6 - 12 . Typically, the user commands the application to load a data object, and uses the application to process the data object. 
     In the user interface environment of the present invention, control from step  1706  may then flow to any number of directions. In some cases, control flows back to step  1704 , as shown in FIG.  17 . 
     5.2 Create a Note/Sub-note (From the Note Menu) 
     One way for the user to issue a command to create a new note or sub-note is to open the note menu  1602  (by pressing the note menu button  409 ), and then select the “New Note/Sub-note” option. In response to this command, the notes application  302  performs the steps of flowchart  1802  in FIG.  18 . 
     In step  1804 , the notes engine  306  of the notes application  302  determines whether a note is currently being displayed in the computer display (i.e., the display unit  2826 ). That is, the notes engine  306  determines whether a notes window (such as notes window  606  in FIG. 6) is currently open in the computer display (which may be a conventional computer monitor or display produced in a VR environment). If a note is not currently being displayed, then step  1810  is performed. Otherwise, step  1806  is performed. 
     In step  1806 , the notes engine  306  determines whether the user has issued a command to close the note that is currently being displayed. The user issues such a command if he wishes to insert the new sub-note in a new note, as opposed to the currently opened note. If the notes engine  306  determines that the user has not issued a command to close the note that is currently being displayed, then step  1812  is performed (described below). In step  1812 , the note currently being displayed is called the active note for reference purposes. Otherwise, step  1808  is performed. 
     In step  1808 , the notes engine  306  closes the note. 
     In step  1810 , the notes engine  306  creates a new note. As represented by a flowchart  1902  in FIG. 19, the notes engine  306  creates a new note by creating a new notes node (such as notes node  1408  in FIG. 14) in the notes database  308  (step  1906 ). The notes engine  306  adds the new notes node to the node linked list  1450  (step  1908 ). Procedures for adding a node to a linked list are well known. The notes engine  306  in step  1910  initializes the new notes node by storing the name of the new note in the note identifier field  1412  (this name is preferably entered by the user). Also, the notes engine  306  in a well known manner stores pointers in next note field  1414  of the active note&#39;s notes node and of other notes nodes (as necessary) so as to add the new notes node in the node linked list  1450 . At this point, the notes application  302  may also prompt the user for security/privacy settings for the new note. Any security/privacy settings input by the user are also stored in the new note. 
     Also at this point, the notes application  302  may receive from the user a command identifying a notes group (either existing or new) to which the notes application  302  should add the new note. If the user provides this information, then the notes application  302  modifies the note grouping table  390  accordingly. 
     Referring again to FIG. 18, also in step  1810 , the user interface  304  opens a notes window (such as notes window  606  in FIG.  6 ), and displays the new note in the notes window. The new note is called the active note for reference purposes. 
     In step  1812 , the notes engine  306  creates a new sub-note. As indicated in a flowchart  2002  in FIG. 20, the notes engine  306  creates a new sub-note by creating a new sub-note node (such as sub-note node  1422 A in FIG. 14) in step  2006 . In step  2008 , the notes engine  306  generates a sub-note identifier for the new sub-note. The sub-note identifier is unique among all sub-notes. The sub-note identifier may be composed of the name of the note (i.e., the active note) concatenated with the current date/time stamp. Other procedures for deriving the sub-note identifier could alternatively be used. In step  2010 , the notes engine  306  stores the sub-note identifier in the sub-note identifier field  1504  of the new sub-note node. The notes engine  306  also stores information identifying the new note in the note identifier field  1503 . In step  2012 , the notes engine  306  adds the new sub-note node to the active note&#39;s sub-note linked list (such as sub-note linked list  1452 ). At this point, the notes engine  306  may also receive a command from the user indicating the privacy/security setting of the new sub-note. If the user enters this information, then the notes engine  306  stores the privacy/setting of the new sub-note in the sub-note privacy settings field  1514 . 
     Referring again to FIG. 18, the user interface  304  in step  1814  enables the user to link the new sub-note to a portion of a data object. It may be necessary for the user to open the data object in a well known manner prior to the performance of step  1814 . Alternatively, the data object may already have been opened by the user. In any case, in step  1814 , the user selects one of the pen buttons  410  in order to obtain a pen. The user then uses this pen (in the manner discussed above) to select a portion of the data object. Procedures for selecting portions of data objects are well known. The procedure for selecting a portion of a data object is dependent on the application associated with the data object. The notes engine  306  commands the application associated with the data object to color code the selected portion using the color associated with the pen. 
     In step  1816 , the notes engine  306  links the selected portion of the data object to the new sub-note. In step  1818 , the notes engine  306  updates the displays of the data object and the active note so as to graphically reflect this linkage. The notes engine  306  performs steps  1816  and  1818  in the manner shown in a flowchart  2102  of FIG.  21 . 
     In step  2106 , the notes engine  306  stores information identifying the data object in the object identifier field  1506  of the new sub-note node. This information may be the file name of the data object, for example. The notes engine  306  may also store in the object identifier field  1506  information identifying the application associated with the data object. The notes engine  306  may obtain the information to be stored in the object identifier field  1506  by querying the application associated with the data object. 
     In step  2108 , the notes engine  306  stores in the location identifier field  1508  of the new sub-note node information that identifies the location of the selected portion in the data object. If the data object is a text document, for example, then this information may comprise page and line information. If the data object is a spreadsheet document, then this information may comprise cell identification information. If the data object is a database document, then this information may comprise record and field identification information. The notes engine  306  preferably obtains this location identification information by querying the application associated with the data object. Also in step  2108 , the notes engine  306  stores in the range field  1509  information that indicates the range of the selected portion in the data object. 
     As discussed above, in some embodiments the object identifier field  1506 , the location identifier field  1508 , and the range field  1509  are partitioned into the note/object linking information database  3408  (along with the link privacy settings  1516 ). All other information is stored in the note information database  3406 . In these embodiments, the notes engine  306  also generates a link address, and stores the link address in both the link address field  3702  of the entry in the note information database  3406  and the link address field  3706  of the corresponding entry in the note/object linking information database  3408 . In some embodiments, the object identifier field  1506 , the location identifier field  1508 , and the range field  1509  are encrypted. Thus, in steps  2106  and  2108  the notes engine  306  encrypts the pertinent data before storing it in these fields. Also in some embodiments, the link address contained in the link address field  3702  of the entry in the note information database  3406  is encrypted. Thus, the notes engine  306  encrypts the link address before storing it in the link address field  3702  of the entry in the note information database  3406 . 
     In step  2110 , the notes engine  306  stores in the pen field  1510  information that identifies the pen that the user used in step  1814  to select a portion of the data object. Preferably, the notes engine  306  stores in the pen field  1510  information identifying the color of the pen, and the symbol associated with the pen. The notes engine  306  may store privacy/security settings information for the sub-note and/or the link in the appropriate fields  1514 ,  1516 , if the user enters this information. 
     In step  2112 , the notes engine  306  commands the application associated with the data object to display a linking button proximate or adjacent to the selected portion. The linking button is displayed using the color of the pen used to select this selected portion, and using the symbol associated with this color (see FIG.  5 ). The notes engine  306  associates the sub-note identifier for the new sub-note with this linking button. In this manner, the notes engine  306  can locate the new sub-note if the user presses the linking button (such operation is described below). 
     In step  2114 , the notes engine  306  displays a linking button (identical to that described in step  2112 ) in the notes window for the active note. The linking button is displayed proximate or adjacent to the sub-note window for the new sub-note (see FIG. 6, for example). The notes engine  306  also displays information identifying the data object in the object field proximate or adjacent to the sub-note window for the new sub-note (such as object field  614  in FIG.  6 ). The notes engine  306  further displays information identifying the location of the selected portion in the location field proximate or adjacent to the sub-note window for the new sub-note (such as location field  616  in FIG.  6 ). 
     Referring again to FIG. 18, the user interface  304  in step  1820  enables the user to enter information in the sub-note window of the new sub-note. Such information can be of any format, such as text, sound, video, tactile, computer program, etc. The notes engine  306  stores this information in the contents field  1512  of the new sub-note&#39;s node. The user may also enter privacy settings at this time for the note, sub-note, or link. The notes engine  306  stores any such information entered by the user in the appropriate fields. 
     5.3 Create a Note/Sub-note (Using a Pen) 
     Another way for the user to issue a command to create a new note or sub-note is to press one of the pen buttons  410 , and then use the resulting pen to select a portion of the data object currently being displayed. A new sub-note is then created and linked to this selected portion. This approach does not require the user to use the note menu  1602 . The operation of the notes application  302  in accordance with this approach is represented by a flowchart  2202  shown in FIG.  22 . 
     In step  2204 , the user selects one of the pen buttons  410  in order to obtain a pen. The user then uses this pen (in the manner discussed above) to select a portion of the data object. The notes engine  306  commands the application associated with the data object to color code the selected portion using the color associated with the pen. 
     In step  2206 , the notes engine  306  of the notes application  302  determines whether a note is currently being displayed in the computer display (in a manner discussed above). If a note is not currently being displayed, then step  2212  is performed (discussed below). Otherwise, step  2208  is performed. 
     In step  2208 , the notes engine  306  determines whether the user has issued a command to close the note that is currently being displayed. The user issues such a command if he wishes to insert the new sub-note in a new note, as opposed to the currently opened note. If the notes engine  306  determines that the user has not issued a command to close the note that is currently being displayed, then step  2214  is performed (described below). (In step  2214 , the note currently being displayed is called the active note for reference purposes.) Otherwise, step  2210  is performed. 
     In step  2210 , the notes engine  306  closes the note. 
     In step  2212 , the notes engine  306  creates a new note (in the manner discussed above). Also in step  2212 , the user interface  304  opens a notes window (such as notes window  606  in FIG.  6 ), and displays the new note in the notes window. The new note is called the active note for reference purposes. 
     In step  2214 , the notes engine  306  creates a new sub-note (in the manner discussed above). The user interface  304  opens a sub-note window in the window for the active note, and displays the new sub-note in this sub-note window. 
     In step  2216 , the notes engine  306  links the selected portion of the data object to the new sub-note (in the manner discussed above). 
     In step  2218 , the notes engine  306  updates the displays of the data object and the active note so as to graphically reflect this linkage (in the manner discussed above). 
     In step  2220 , the user interface  304   1820  enables the user to enter information in the sub-note window of the new sub-note. Such information can be of any format, such as text, sound, video, tactile, computer program, etc. The notes engine  306  stores this information in the contents field  1512  of the new sub-note&#39;s node. Any security/privacy settings entered by the user are also stored. 
     5.4 View Note (By Selecting a Linking Button in a Data Object) 
     One way for the user to issue a command to view an existing sub-note is to select (using the well known point-and-click approach) the linking button displayed proximate to the portion of the data object that is linked to the sub-note. For example, in FIG. 6, the user can issue a command to view Sub-note A 1  by selecting the linking button  604  next to the portion  602  of the patent data object that is linked to Sub-note A 1 . The operation of the notes application  302  in this regard is represented by a flowchart  2302  in FIG.  23 . 
     In step  2304 , the user selects the linking button displayed proximate to the portion of the data object of interest. For illustrative purposes, suppose that the user clicked on the linking button  1218  corresponding to portion  1216  of the audio data object titled “XYZ” (FIG.  12 ). 
     In step  2306 , the notes engine  306  in response to this user action identifies the note and sub-note corresponding to linking button  1218 . The manner in which the notes engine  306  performs step  2306  is represented by a flowchart  2402  in FIG.  24 . In step  2406 , the notes engine  306  identifies the sub-note identifier that is associated with the linking button  1218 . The linking button  1218  preferably has stored with it the sub-note identifier (or some other type of pointer or address to a sub-note). In step  2408 , the notes engine  306  searches in a well known manner through the notes database  308  until it locates the sub-note having the sub-note identifier determined in step  2406 . For illustrative purposes, assume that the notes engine  306  in step  2408  determines that Sub-note B 5  (see FIGS. 12 and 14) has the sub-note identifier determined in step  2406 . 
     In step  2320 , the notes engine  306  determines whether security/privacy criteria associated with the link (corresponding to the linking button), the sub-note (identified in step  2306 ), and the note (identified in step  2306 ) are satisfied. The notes engine  306  retrieves this security/privacy criteria information from the associated note node and sub-note node, and then compares the retrieved security/privacy criteria information to the situation at hand. For example, if the security/privacy criteria is keyed to the current user&#39;s password, then the notes engine  306  compares the password of the current user (which the current user previously entered, or is now asked to enter) with that retrieved from the note and/or sub-note. If the security/privacy criteria is not satisfied, then the user cannot view the note and/or sub-note. If this is the case, then an error message is displayed in step  2322 . If the security/privacy criteria is satisfied, then control flows to step  2308 . 
     In step  2308 , the notes engine  306  determines whether the note that includes the sub-note identified in step  2306  is currently being displayed in the computer display. In the example discussed above, the notes engine  306  in step  2308  determines whether Note B is currently being displayed in the computer display. If Note B is currently being displayed in the computer display, then control flows to step  2312  (described below). Otherwise, step  2310  is performed. 
     In step  2310 , the notes engine  306  displays in a notes window the note that includes the sub-note identified in step  2306 . 
     In step  2312 , the notes engine  306  scrolls through the note in the notes window until the sub-note identified in step  2306  is displayed in the notes window. 
     5.5 View Note (From the Note Menu) 
     Another way for the user to issue a command to view an existing sub-note is to select the “View Note” command from the note menu  1602 . The operation of the notes application  302  upon receipt of such a command is represented by a flowchart  2502  in FIG.  25 . 
     In step  2504 , the user interface  304  displays a list of all existing notes (this list includes the names of all such existing notes). 
     In step  2506 , the user selects one of these notes in a well known manner. For illustrative purposes, assume that the user selected Note B (FIG.  12 ). 
     In step  2550 , the notes engine  306  determines whether security/privacy criteria associated with the note and the sub-notes in the note are satisfied. The notes engine  306  retrieves this security/privacy criteria information from the associated note node and sub-note nodes, and then compares the retrieved security/privacy criteria information to the situation at hand. For example, if the security/privacy criteria is keyed to the current user&#39;s password, then the notes engine  306  compares the password of the current user (which the current user previously entered, or is now asked to enter) with that retrieved from the note and/or sub-notes. If the security/privacy criteria is not satisfied, then the user cannot view the note and/or sub-note. If this is the case, then an error message is displayed in step  2552 . If the security/privacy criteria is satisfied for at least the note, then control flows to step  2508 . 
     In step  2508 , the notes engine  306  retrieves the selected Note B and its Sub-notes B 1 -B 5  from the notes database  308 . The user interface  304  then displays Note B and its Sub-notes B 1 -B 5  in a notes window  904 , as shown in FIG.  12 . 
     As discussed above, the user can display the portions of the data objects linked to the Sub-notes B 1 -B 5  by pressing the linking buttons  910 ,  1010 ,  1110 ,  1222 ,  1230  located proximate to the sub-note windows  908 ,  1008 ,  1108 ,  1220 ,  1228  in the notes window  904 . Such functionality is represented by steps  2510 - 2516  in FIG.  25 . 
     Specifically, in step  2510  the user clicks on one of the linking buttons  910 ,  1010 ,  1110 ,  1222 ,  1230  in the notes window  904 . The sub-note associated with the linking button selected by the user is called the selected sub-note for reference purposes. For illustrative purposes, assume that the user clicks on linking button  910  corresponding to Sub-note B 1 . As discussed above, Sub-note B 1  is linked to portion  902  of spreadsheet  804  (FIG.  9 ). 
     In step  2552 , the notes engine  306  determines whether security/privacy criteria associated with the link (corresponding to the linking button) is satisfied. The notes engine  306  retrieves this security/privacy criteria information from the associated sub-note node, and then compares the retrieved security/privacy criteria information to the situation at hand. If the security/privacy criteria is not satisfied, then the user cannot traverse the link to view the data object portion. If this is the case, then an error message is displayed in step  2552 . If the security/privacy criteria is satisfied, then control flows to step  2512 . 
     In step  2512 , the notes engine  306  determines whether the data object containing the portion that is linked to the selected linking button is open. In the current example, the notes engine  306  in step  2512  determines whether the spreadsheet  804  is open. If the data object is open, then step  2516  is performed (described below). Otherwise, step  2514  is performed. 
     In step  2514 , the notes engine  306  invokes the application associated with the data object 
     In step  2516 , the notes engine  306  commands the application to present the portion  902  that is linked to the selected linking button  910 . Thus, with reference to FIG. 9, the notes engine  306  in step  2516  commands the spread sheet  804  to scroll (if necessary) such that portion  902  is displayed in the window  802 . It should be noted that the manner for presenting the linked portion is implementation dependent, and is defined by the application associated with the data object. In some cases, for example, the application displays text (where the linked portion is text). In other cases, the application plays a video clip or a sound clip (where the linked portion is video or audio). In other cases, the application executes a computer program (where the linked portion is a computer program). Thus, the manner in which the application presents (or displays) the linked portion in step  2516  is application specific, and depends in large part on the nature, content, and/or format of the linked portion. 
     The manner in which the notes engine  306  performs steps  2512 ,  2514 , and  2516  is represented by a flowchart  2602  in FIG.  26 . 
     In step  2606 , the notes engine  306  identifies the application that is associated with a data object. The notes engine  306  identifies this application by reference to the information in the object identifier field  1506  of the selected sub-note&#39;s sub-note node. The notes engine  306  may need to decrypt this information. 
     In step  2608 , the notes engine  306  determines in a well known manner whether this application is currently executing. If the application is not executing, then in step  2610  the notes engine  306  invokes the application in a well known manner. Then, step  2612  is performed (described below). If the application is already running, then step  2620  is performed. 
     In step  2620 , the notes engine  306  determines whether the data object is loaded in the application by querying the application. If the data object is loaded, then step  2614  is performed. Otherwise, step  2612  is performed. 
     In step  2612 , the notes engine  306  commands the application to load the data object. 
     In step  2614 , the notes engine  306  commands the application to present the portion  902  of the data object that is linked to the selected sub-note. The notes engine  306  does this by retrieving the location and range information contained in the location identifier field  1508  and the range field  1509  of the selected sub-note&#39;s sub-note node. The notes engine  306  may need to decrypt this information. The notes engine  306  then commands the application to present the portion of the data object identified by the retrieved location information. 
     In step  2616 , the notes engine  306  commands the application to display the linking button (in the manner described above) proximate to the portion of the data object as displayed in step  2614 . 
     The user can use the linking buttons  910 ,  1010 ,  1110 ,  1222 ,  1230  in Note B as described above to traverse to any of the portions of data objects linked to the sub-notes associated with the linking buttons  910 ,  1010 ,  1110 ,  1222 ,  1230 . Such flow of control is represented by control arrow  2517  in FIG.  25 . 
     5.6 Select View 
     Flowchart  3902  in FIG. 39 represents the operation of the notes application  302  when processing a command by the user to select a view. 
     In step  3904 , the user enters a command indicating the desired view. As described above, the invention supports a note view, an object view, a link view, and a user defined view. 
     If the user&#39;s command indicates the note view, then step  3906  is performed. In step  3906 , the user selects a note to view utilizing any of the note selection procedures discussed herein. 
     In step  3908 , the notes application  302  verifies that the security/privacy criteria associated with the selected note is satisfied. Such verification is described above. If the security/privacy criteria is not satisfied for the note, then the user is not allowed to view the note. Accordingly, an error message is displayed in step  3932 . Otherwise, step  3910  is performed. 
     In step  3910 , the notes application  302  retrieves the note and its sub-notes from the notes database  308 . The notes application  302  displays the note and its sub-notes in the note view. An example note view is shown in FIG.  30 . Step  3910  is performed as follows. The notes application  302  displays the note in a note window, such as note window  3004 . The notes application  302  retrieves the note&#39;s sub-notes. If the security/privacy criteria associated with a sub-note is satisfied, then the sub-note is displayed in the note window  3004 . Otherwise, the sub-note is not displayed in the note window  3004 . The notes application  302  then determines whether to display the data object portions linked to those sub-notes that are displayed. If the security/privacy criteria associated with the link for each of these sub-notes is satisfied, then the notes application  302  retrieves and displays the linked data object portion in an application window, and displays a bidirectional arrow indicating the link between the data object portion and the sub-note. 
     If, in step  3904 , the user&#39;s command indicates the object view, then step  3912  is performed. In step  3912 , the user selects a data object to view using any selection mechanism discussed herein. The notes application  302  then causes the data object to be retrieved and displayed in an application window. Note that portions of the data object may be linked to sub-notes in the notes database  308 . Such sub-notes are called linked sub-notes. 
     The notes application  302  next determines whether to display the linked sub-notes. Such linked sub-notes would be displayed using the object view (shown in FIG. 31, for example). In step  3914 , the notes application  302  verifies that the security/privacy criteria associated with a linked sub-note, and the linked sub-note&#39;s associated note and link are satisfied. Such verification is described above. If the security/privacy criteria associated with the linked sub-note, its link, and/or its note are not satisfied, then the linked sub-note is not displayed. Control moves to step  3917  (described below). Otherwise, the linked sub-note is displayed in step  3916  as shown in FIG.  30 . 
     In step  3917 , the notes application  302  selects the next linked sub-note to process. Control then returns to step  3914 . 
     It is noted that steps  3914 ,  3916 , and  3917  are performed as other linked data object portions come into view in the application window (due to scrolling by the user, for example). 
     Referring again to step  3904 , if the user&#39;s command indicates the link view, then step  3918  is performed. In step  3918 , the user selects a starting point for the link view. The starting point may be a note grouping, a note, a sub-note, a link, or a data object portion. Assume, for example purposes, that the user selects Note B in FIG. 29 as the starting point. 
     In step  3922 , the notes application  302  searches through the notes database  308  to identify note groupings, notes, sub-notes, and data object portions that are directly or indirectly connected/linked to the starting point. This may be a multiple iteration or recursive search. Such searches are well known. The notes application  302  then displays representations of the identified note groupings, notes, sub-notes, and data object portions using the link view (see the example in FIG.  29 ). Such representations do not include the contents of these items. Instead, they preferably include the name of the item (such as “Sub-note D”) displayed within a graphical construct (such as an oval). 
     Note that in the embodiment described above, the display of the link view does not involve a security check. Security is verified if the user attempts to view the contents of or traverse a note grouping, note, sub-note, link, or data object. In other embodiments, security is verified before even the link view is displayed. 
     Referring again to step  3904 , if the user&#39;s command indicates the user-defined view, then step  3924  is performed. In step  3924 , the user enters search criteria. 
     In step  3926 , the notes application  302  searches through the notes database  308  and identifies note groupings, notes, sub-notes, links, and data objects that satisfy the search criteria. 
     In step  3928 , the notes application  302  verifies that security is satisfied with these identified items. If security is not satisfied with any of these items, then an error message is displayed in step  3932 . If security is satisfied with at least some of these items, then step  3930  is performed. 
     In step  3930 , the notes application  302  displays any of the items for which security was verified. Preferably, a default view is used, such as the standard note view. The user can elect to view the search results using any other view. 
     5.7 Modify Privacy/Security Settings 
     Flowchart  4002  in FIG. 40 represents the operation of the invention when enabling the user to modify the privacy/security settings associated with a note grouping, note, sub-note, or link. 
     In step  4004 , the user selects a note grouping, note, sub-note, or link using any of the selection procedures discussed herein. 
     In step  4006 , the notes application  302  verifies that the privacy/security criteria associated with the selected item is satisfied. Such verification is described above. If the privacy/security criteria is not satisfied, then the user is not allowed to modify the privacy/security settings. In this case, an error message is displayed in step  4010 . If the privacy/security criteria is satisfied, then in step  4008  the user is allowed to enter new privacy/security settings for the selected item. This new privacy/security setting is then stored. 
     5.8 Find Note/Sub-note 
     The user initiates a note/sub-note search by selecting the “Find” command in the note menu  1602 . The operation of the notes application while performing searching is represented by a flowchart  2702  in FIG.  27 . In step  2704 , the user interface  304  enables the user to enter search criteria. The search criteria includes key words, icons, user names, creator names, owner names, date/time stamp, etc. The user can also limit the search to one or more branches of the note grouping/note/sub-note hierarchy. In step  2706 , the notes engine  306  searches through the sub-notes in the notes database  308  (as limited by the user) to locate any and all notes and/or sub-notes which match the search criteria. In step  2708 , the user interface  304  displays the notes containing these sub-notes. Each note is displayed in a separate notes window. 
     5.9 Edit One or More Notes 
     The present invention allows users to modify the sub-notes that are in notes. For example, a user may rearrange the ordering of sub-notes within a note. The user can delete sub-notes from a note. The user can also copy (replicate) or move sub-notes from one note to other notes. The user can also move, delete, or otherwise modify the notes that are in the note groups. The user can also modify the linkage between sub-notes and data object portions. In other words, the invention allows the user to easily modify the note grouping/note/sub-note hierarchy. Such operation of the present invention is represented by step  1708  in FIG.  17 . Step  1708  is discussed in detail below. 
     A user rearranges sub-notes in a note, or moves/copies sub-notes between notes by selecting the desired sub-notes, and then dragging and dropping the selected sub-notes to the desired locations. In FIG. 13, for example, assume that the user wishes to move Sub-note B 1  so that it is displayed between Sub-notes B 3  and B 4 . In this case, the user selects Sub-note B 1  in a well known manner, and then drags selected Sub-note B 1  until it is located between Sub-notes B 3  and B 4 . The user then drops Sub-note B 1  between Sub-notes B 3  and B 4  in a well known manner. 
     Suppose that the user wishes to move Sub-note B 1  to Note C. In this case, the user selects Sub-note B 1  in a well known manner, and then drags selected Sub-note B 1  until it is positioned over Note C. The user then drops Sub-note B 1  into Note C. 
     The user modifies the notes within a note group and the linkage between sub-notes and data object portions in a similar manner. 
     In response to such user commands, the notes engine  306  moves/copies sub-notes between the sub-note linked lists, modifies the note grouping table  390 , and/or modifies the linkage information in the sub-note nodes. Procedures for deleting nodes from linked lists, inserting nodes into linked lists, and moving nodes between linked lists are well known. 
     6. Applications of the Invention 
     The invention is applicable to any application that would benefit from the enhanced organization of information. Such applications include, but are not limited to: (1) law related projects, such as licensing studies, litigation efforts, opinions of counsel (such as patentability, patent validity, and patent infringement studies); (2) scientific and/or engineering related projects, such as research and development projects; (3) electronic text books, handbooks, user manuals, encyclopedias, and other electronic reference works, including multimedia reference works; (4) auditory and visual documents; (5) virtual library; (6) review course, such as legal bar review course, business review courses, CPA courses, medical review courses, etc.; and (7) virtual classrooms. 
     Other applications of the invention will be apparent based on the discussion contained herein. Two such applications are discussed in some detail below. 
     6.1 Movie Production 
     The invention is applicable to the entertainment industry, such as the motion picture industry. The invention could be used to organize the great amounts of information that is collected and generated during the development of a movie. This scenario is represented in simplified form in FIG.  46 . 
     Generally, a movie is developed in three phases: a pre-production phase, a production phase, and a post production phase. The present invention could be used to organize, memorialize, and institutionalize the information collected and generated during these phases. Specifically, a note  4602  could be created for the pre-production phase. Also, a note  4604  could be created for the production phase, and another note  4606  could be created for the post production phase. 
     The pre-production note  4602  could include sub-notes that link to data objects used to research the movie&#39;s topic. For example, suppose the movie involved lions. One sub-note, called Sub-note A, could be linked to a chapter in a book  4626  dealing with lions. Another sub-note, Sub-note B, could be linked to a segment of a video  4628  pertaining to lions. Other sub-notes, such as Sub-notes C-E, could be linked to drafts  4630  of the script. These sub-notes could include comments/edits on the drafts  4630 . Other sub-notes (not shown) could be linked to other pre-production related objects, such as contracts with actors, travel itineraries, budget reports, purchase orders for costumes and props, etc. 
     The production note  4604  could include sub-notes that are linked to production data objects, such as the final draft of the script  4634 , various scenes  4634 , various takes  4634 , clips, shots, frames, etc. Such scenes  4634 , takes  4634 , clips, shots, and frames would be in a form useable by a computer. 
     The post production note  4606  could include sub-notes that are linked to post-production data objects, such as the theatrical production  4624  of the movie, the video production  4624  of the movie, the movie soundtrack, etc. 
     There are many advantageous for using the present invention to create movies. First and perhaps foremost, the present invention will lend order to the creation of a movie and to the memorialization and documentation of the movie production. Accordingly, movie production will be more efficient and effective. 
     Second, the use of the invention to create movies will create great marketing opportunities. Currently, there is limited distribution of movies and their related materials. For most movies, only the theatrical version and perhaps the home video version are sold and distributed. Limited source materials (such as the “Making of” type publications) are available to the public. 
     The present invention allows any and all versions of any given movie to be easily packaged, distributed and sold. One need only copy the pertinent notes, sub-notes, and data objects to a computer readable medium (such as one or more compact disks), and distribute and sell copies of the computer readable medium to the public. 
     Also, for movie historians and other interested parties, the materials that were used to create the movie (such as the pre-production information and the production information) can be easily packaged, distributed, and sold. Again, one need only copy the pertinent notes, sub-notes, and data objects to a computer readable medium, and distribute and sell copies of the computer readable medium to the public. 
     Further, the use of the invention will enable movie aficionados to create their own versions of a movie. This is the case, since the soundtrack, scenes, takes, clips, shots, and/or frames are stored as data objects, and are linked to sub-notes. Such personalized movie making packages can be easily packaged, distributed, and sold. Again, one need only copy the pertinent notes, sub-notes, and data objects to a computer readable medium, and distribute and sell copies of the computer readable medium to the public. 
     6.2 Bar Review Program 
     The invention could be used to create attorney bar review course materials. These materials could be used as a supplement to a traditional bar review course, or as an alternative to a bar review course. 
     A portion of an example notes database  308  for a bar review course is shown in FIG.  47 . Bar review course materials typically include a number of sample tests. According to the present invention, a note is associated with each question of each sample test. For example, note  4702  is associated with Question  1 . Sub-note A is linked to the portion  4706  of a sample test data object  4704  that corresponds to Question  1 . Sub-note B is linked to the portion  4708  of the sample test data object  4704  that corresponds to the answer to Question  1 . 
     Suppose that Question  1  pertains to an area of Torts law. Question  1  note  4702  may also include a Sub-note C that is linked to a portion  4716  of a torts text  4714  in an electronic legal library  4712 . This portion  4716  deals with the substantive torts law of Question  1 . A student may find it very useful to study this portion  4716  when working with Question  1 . 
     The notes database  308  could also include a torts note  4710  that the deals specifically with torts. This torts note  4710  could have sub-notes, such as Sub-notes G and H, that are linked to portions of the torts text  4714 . Sub-notes G and H could have commentary on these portions of the torts text  4714 . The Question  1  note  4702  could then have a Sub-note D that points to Sub-note G in the torts note  4710 . Sub-note G points to the same portion  4716  in the torts text  4714  pointed to by Sub-note C (typically, the Question  1  note  4702  would include Sub-note C or Sub-note D, but not both). Notes dealing with questions other than Question  1  could then point to the sub-notes in the torts note  4710 , as necessary, thereby enhancing reusability. 
     The notes database  308  could also include a case analysis note  4726  that includes sub-notes that point to cases in electronic case reporters  4722 . These sub-notes could include commentary and analysis of such cases. The Question  1  note  4702  could include a Sub-note E that is linked to a Sub-note F in the case analysis note  4728 . This Sub-note F is linked to a case  4724  that deals with the issues of Question  1 . Students may find it useful to review this case  4724  when working with Question  1 . 
     7. Conclusion 
     While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.