Patent Publication Number: US-7590619-B2

Title: Search system using user behavior data

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The subject matter described herein is related to the subject matter disclosed in co-pending U.S. patent application Ser. No. 10/727,444, filed Dec. 3, 2003, entitled “Search System Using User Behavior Data”. 
   FIELD OF THE INVENTION 
   This invention relates in general to the field of data search and retrieval. More particularly, this invention relates to the collection and use of user behavior data for data search and retrieval. 
   BACKGROUND OF THE INVENTION 
   Data stored on one or more computer systems may be useful for a user. However, the stored data may be too extensive for a user to find the data by direct examination. Additionally, some parts of a data repository may contain information that is not accessible to the user. In many cases, in order to allow the user useful access to the data, a search mechanism is provided. The search mechanism allows a user to issue a search request (also termed a search query). The query is executed and the results are returned for the user. 
   For example, a web-based search engine is a search mechanism that is used to provide search access to information via a web-based search. The information may be found in a specific data repository, such as a database or other data collection. The information may also be an agglomeration of data found in a number of different data repositories. Such a search engine may provide search access to information available from different information providers over a network, such as the Internet. 
   In a typical usage of a web search engine, the user enters a query, which is a set of search terms related to what the user is looking for. The query is transmitted to the search engine, which attempts to locate “hits”—i.e., content that is available on the Internet and that relates to the terms contained in the query. Generally, the search engine either has a database of web pages that are known to exist, or communicates with external “providers” who maintain such databases; the query is “scored” against items in these databases to identify the web pages that best match the query. A list of results is then generated, and these results are returned to the user&#39;s computer for display by the user&#39;s web browser. 
   Typically, the databases contain information such as: the Uniform Resource Locators (URLs) of web pages, the titles of the pages, descriptions of the pages, and possibly other textual information about the web pages. The user then reads the results and attempts to determine, based on the text contained in the results, whether the results correspond to what the user is looking for. Users may then attempt to retrieve the entire page correlating to a search result. In other contexts, search engines present results summarizing the pieces of data that may possibly be useful for a user. 
   The utility of the search engine is correlated directly to the quality of the results provided. In the best case, the results are presented to the user in order of utility to the user on the result page. Because the quality of the results is subjective, the user&#39;s satisfaction must be determined in order to determine whether the quality of the results were satisfactory. 
   In the prior art, quality of individual web pages has been measured by obtaining explicit feedback from a user. At least one prior art web browser has attempted to obtain such explicit feedback from a user. This browser is described in a paper entitled “Inferring User Interest” by Mark Claypool, David Brown, Phong Le, Makoto Waseda in  IEEE Internet Computing  5(6): 32-39 (2001). In that browser, different pages are displayed by the browser. Whenever the page being displayed by the browser is changed, a user evaluation of the page is requested from the user. User evaluations for a given page are collected, to determine whether users find that page valuable. In this browser, some implicit feedback is also maintained regarding each page, including data regarding the time spent on the page, mouse movements, mouse clicks, and scrolling time. 
   While this technique does gather user feedback, it has limited utility in situations in which users may have different needs for a page. For example, a user who is looking for information about books written by Douglas Adams may evaluate a page on his book  The Hitchhiker&#39;s Guide to the Galaxy  and give a high score for utility. However, another user who is looking for information on books about traveling cheaply may evaluate the same page and give it a low score. Thus the technique described will have limited utility in the wide variety of situations in which different users may have different needs, or even where a single user may have different needs for information at different times. In other words, the usefulness of this technique is limited because evaluation of each page is completely independent of the context in which the user arrived at the page. 
   Thus, this technique is not useful for evaluating the quality of a search engine. In general, this technique is not useful for evaluations that are context-based, but only for evaluating the quality of individual data items, independent of the context in which a user arrived at the data items. 
   Another drawback of the prior art is that users may respond to explicit requests for feedback by ignoring them or providing inaccurate feedback in order to speed the searches the users are performing. This leads to possibly unreliable data in addition to user dissatisfaction with the search tool. 
   Additionally, the prior art web browsers do not request feedback on non-standard search results. Many web searches now provide non-standard search results. For example, when searching web pages, for example, for a restaurant of a specified name in a specified town, some web searches simultaneously do a phone book search for the phone number of the restaurant. This result is displayed for the user. This is a non-standard result because it is not the type of result that the user was ostensibly requesting. However, it may be useful to judge the satisfaction of the user with such non-standard results. 
   An additional problem in judging satisfaction with search results is that they may be used by a user without the user selecting the result (standard or non-standard) and without the user otherwise indicating through other implicit feedback that the user has found a satisfactory result. In the above example, a user who is only looking for a web page regarding the restaurant to find the phone number of the restaurant may find that phone number in a non-standard result and use that information without selecting any result, standard or non-standard. 
   Another drawback of the prior art is that feedback from each user is considered without reference to the user making the feedback. A user with a different experience level, language, purpose, or technical ability may have different responses to the search mechanism, however there is no way to include such differences in considering user satisfaction according to the prior art systems. 
   Thus, there is a need for a system and method to overcome these deficits in the prior art. The present invention addresses the aforementioned needs and solves them with additional advantages as expressed herein. 
   SUMMARY OF THE INVENTION 
   User behavior data (explicit feedback and/or implicit feedback) on a search performed on a search mechanism is collected along with the context for that user behavior data. This allows context-dependent evaluations of the quality of search mechanisms. Because both context data (describing the search) and user feedback data (the user&#39;s feedback on the search—either explicit or implicit) are collected, data necessary for an evaluation of the search is available. This information can be used, for example, to evaluate a search mechanism or to check a relevance model. 
   In one embodiment, context information concerning a user is collected. Such context information, in one embodiment, includes one or more of: the speed of a user&#39;s connection to the search mechanism; the type of connection; the user&#39;s self-classification of their use of the search mechanism (e.g. from among business, school, or personal use); background information concerning the user (e.g. the user&#39;s technical competency level); and language information about the language being used to perform the search. 
   In one embodiment, explicit feedback is not collected for each search. Rather, in one embodiment, a snooze request may be issued by a user. If a snooze request is issued, for a period of time, explicit feedback is not collected. This is done in order to enhance usability for a user, by providing a way for the user to “turn off” the explicit feedback requests, which the user may not always wish to answer at a specific time. In another embodiment, a target value for the number of requests issued to a user or for the percentage of time that explicit feedback is requested is set. Explicit feedback is requested at some times, but not requested at others, in order to attempt to approximately meet the target value for requesting explicit feedback. 
   In one embodiment, the explicit feedback collected includes feedback regarding satisfaction with queries in general, with results pages, and with individual results visited. Explicit feedback concerning satisfaction with individual results not visited is also collected. For example, where a number of results are presented and several results are selected and explored, explicit feedback is collected regarding a non-selected result. As another example, in a search mechanism in which a non-standard search result is presented, explicit feedback about a non-standard search result not selected is requested. Where a user performs a web search for web pages concerning a city, for example, and text including a weather report for that city is presented as a non-standard result for the search (along with standard results including web pages concerning the city), a user is asked for their explicit feedback on the weather report presented to the user. 
   In one embodiment, implicit feedback data collected includes: whether a requery was performed by the user, what the dwell and click time on the results page was, what the position of results clicked was (absolute position and page position), whether additional results were requested by the user (e.g. by clicking “next” for a next set of results), and destination page dwell time, page size, or page actions. 
   Other features of the invention are described below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing summary, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings example constructions of the invention; however, the invention is not limited to the specific methods and instrumentalities disclosed. In the drawings: 
       FIG. 1  is a block diagram of an example computing environment in which aspects of the invention may be implemented; 
       FIG. 2  is a block diagram of an example architecture according to one embodiment of the invention; 
       FIG. 3  is a flow diagram showing the process of gathering context-based feedback including user information according to one embodiment of the invention; 
       FIG. 4  is a flow diagram showing the process of gathering context-based feedback including explicit feedback according to one embodiment of the invention; and 
       FIG. 5  is a flow diagram showing the process of gathering context-based feedback including explicit feedback on non-selected results according to one embodiment of the invention. 
   

   DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
   Overview 
   User feedback (explicit and/or implicit) is collected along with the context for that feedback. This allows context-dependent evaluations of the quality of search mechanisms. If one search mechanism produces results that garner better feedback than a second search mechanism, it can be determined that the first search mechanism is more successful at finding results for a user. This information can be used, for example, to create a relevance model to measure the effectiveness of a search system. 
   In one embodiment, context-based search mechanism user feedback is captured by tracking an event stream and following a state machine in order to determine the state of the user&#39;s interaction with the browser. This allows queries to be presented to the user in order to (1) track what state the interaction is in and (2) request explicit feedback from the user. Implicit feedback, such as the amount of time spent on a page, among other implicit feedback items, is also tracked. This feedback information allows a determination to be made of whether a search result was useful in the context of the original search. Once this data has been collected, it can be analyzed to determine the quality of the search mechanism used. It can also be used to test a relevance model and see if the predictions generated by the relevance model on the quality of the results generated match the actual quality of the results as shown in implicit and/or explicit user feedback. 
   Thus, implicit and explicit end-user behavior is collected along with search context in order to provide increased accuracy in predicting user satisfaction. 
   Exemplary Computing Environment 
     FIG. 1  shows an exemplary computing environment in which aspects of the invention may be implemented. The computing system environment  100  is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment  100  be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment  100 . 
   The invention is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with the invention include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, embedded systems, distributed computing environments that include any of the above systems or devices, and the like. 
   The invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network or other data transmission medium. In a distributed computing environment, program modules and other data may be located in both local and remote computer storage media including memory storage devices. 
   With reference to  FIG. 1 , an exemplary system for implementing the invention includes a general purpose computing device in the form of a computer  110 . Components of computer  110  may include, but are not limited to, a processing unit  120 , a system memory  130 , and a system bus  121  that couples various system components including the system memory to the processing unit  120 . The processing unit  120  may represent multiple logical processing units such as those supported on a multi-threaded processor. The system bus  121  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus (also known as Mezzanine bus). The system bus  121  may also be implemented as a point-to-point connection, switching fabric, or the like, among the communicating devices. 
   Computer  110  typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computer  110  and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CDROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by computer  110 . Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media. 
   The system memory  130  includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM)  131  and random access memory (RAM)  132 . A basic input/output system  133  (BIOS), containing the basic routines that help to transfer information between elements within computer  110 , such as during start-up, is typically stored in ROM  131 . RAM  132  typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit  120 . By way of example, and not limitation,  FIG. 1  illustrates operating system  134 , application programs  135 , other program modules  136 , and program data  137 . 
   The computer  110  may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only,  FIG. 1  illustrates a hard disk drive  141  that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive  151  that reads from or writes to a removable, nonvolatile magnetic disk  152 , and an optical disk drive  155  that reads from or writes to a removable, nonvolatile optical disk  156 , such as a CD ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive  141  is typically connected to the system bus  121  through a non-removable memory interface such as interface  140 , and magnetic disk drive  151  and optical disk drive  155  are typically connected to the system bus  121  by a removable memory interface, such as interface  150 . 
   The drives and their associated computer storage media discussed above and illustrated in  FIG. 1 , provide storage of computer readable instructions, data structures, program modules and other data for the computer  110 . In  FIG. 1 , for example, hard disk drive  141  is illustrated as storing operating system  144 , application programs  145 , other program modules  146 , and program data  147 . Note that these components can either be the same as or different from operating system  134 , application programs  135 , other program modules  136 , and program data  137 . Operating system  144 , application programs  145 , other program modules  146 , and program data  147  are given different numbers here to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer  20  through input devices such as a keyboard  162  and pointing device  161 , commonly referred to as a mouse, trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit  120  through a user input interface  160  that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor  191  or other type of display device is also connected to the system bus  121  via an interface, such as a video interface  190 . In addition to the monitor, computers may also include other peripheral output devices such as speakers  197  and printer  196 , which may be connected through an output peripheral interface  195 . 
   The computer  110  may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer  180 . The remote computer  180  may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer  110 , although only a memory storage device  181  has been illustrated in  FIG. 1 . The logical connections depicted in  FIG. 1  include a local area network (LAN)  171  and a wide area network (WAN)  173 , but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. 
   When used in a LAN networking environment, the computer  110  is connected to the LAN  171  through a network interface or adapter  170 . When used in a WAN networking environment, the computer  110  typically includes a modem  172  or other means for establishing communications over the WAN  173 , such as the Internet. The modem  172 , which may be internal or external, may be connected to the system bus  121  via the user input interface  160 , or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer  110 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation,  FIG. 1  illustrates remote application programs  185  as residing on memory device  181 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. 
   Architecture 
   In one embodiment, the invention is implemented in or in conjunction with a web browser. A block diagram of an exemplary architecture is shown in  FIG. 2 . The browser,  200 , is a web browser, which the user interacts with. A browser helper object  210  interfaces with the browser  200 , captures browser events, and send the events to a user behavior tracer  220 . The core part of user behavior tracer  220  is state machine  225 . The states of the state machine  225  represent the state of the user&#39;s interaction with browser  200 . For example, one state may be associated with the user having initiated a search, but not yet received a result page. The state machine  225  receives events from user behavior tracer  220 , tracks the state of the user&#39;s behavior as the user uses the browser  200 , and collects implicit and explicit user feedback. The user behavior tracer  220  sends data regarding the search and the feedback to the data acquisition engine  230  which stores or processes the data. 
   In one embodiment, a Component Object Model (COM) or similar interface in browser  200  is used to allow an in-process COM server (or equivalent) to be developed which uses the interface in browser  200 . This in-process COM server or equivalent is the browser helper object  210 . The browser helper object  210  can, in one embodiment, be an in-process COM component registered under a certain registry key. When browser  200  is started, it looks up that registry key and loads the object whose class ID (CLSID) is stored there. (A CLSID is a globally unique identifier that identifies a COM class object.) 
   Browser helper object  210  detects the browser&#39;s typical events. In some browsers, events occur (are “fired”) when certain situations occur. The detection of the event can signal that certain situations have occurred in the browser. For example, such events may include events which indicate the user&#39;s navigation from page to page, such as: (1) an event which fires when a hyper link has been clicked to navigate to a different page; (2) an event which fires when the history is used for navigation to a different page; (3) an event which fires when the address bar is used to navigate to a different page; and/or (4) an event which fires when the favorites list is used to navigate to a different page. 
   Additionally, such events may be include events which indicate the user&#39;s use of a displayed page, such as: (5) an event which fires when a document has been completely loaded and initialized (6) an event which fires when scrolling is taking place; (7) an event which fires when a document is printed; (8) an event which fires when a document is added to the favorites list; (9) an event which fires when the window gains focus; (10) an event which fires when the window loses focus; and/or (11) an event which fires when a window has been closed. Other events may also exist and may be detected by the browser helper object  210 . Some of these events may not be available in some browsers  200 , and some browsers  200  may require modification in order to provide functionality for detection of these browsers. 
   In addition, other events may be useful for determining the user&#39;s satisfaction with a search. At least the following events may be detected by the browser helper object  210 : (12) the same query performed again by a specific user, with minor modifications (requery); (13) the dwell time spent by a user on the result page; (14) the time it takes for a user to click on or otherwise select an item on the results page (click time); (15) the position of the result selected by the user on the results page; (16) whether more results are requested by the user (e.g. by selecting a “more” function on a results page or by requesting “additional results like these”); (17) the dwell time spent by the user on a result; (18) the result page size; and (19) result page actions—those actions performed on a result page, such as printing a result page. 
   In addition to notification of the occurrence of the corresponding activity in the browser, these events in some cases also include information about the activity. For example, when a hyperlink has been clicked (event 1) the element which has been clicked is sent as a parameter in the event. 
   In addition to detecting these events which signal the user&#39;s pattern of navigation and the user&#39;s use of a displayed page, browser helper object  210  can also access the browser&#39;s menu and toolbar and install hooks to monitor messages and actions which are not reflected in events. In one embodiment, these hooks are used instead of the use of events as detailed above. 
   Once this information is captured by the browser helper object  210 , it is passed to the user behavior tracer  220 . The events are used in two ways. First, the event may be stored as or used to calculate implicit feedback data. Such implicit feedback may include: data regarding the time spent on the page, mouse movements, mouse clicks, scrolling time, and query text entered. Additionally, implicit feedback may include event date and time stamps, result positions on page, link text, result URL, result click-through, result dwell-time, result printed, result added to My Favorites, scrolling activity detected on result, and whether the result was a sponsored link. 
   In addition to the use of the data from the browser helper object  210  for implicit feedback, the data, in one embodiment, is also used to transition from one state to another or to trigger an event in the state machine. Events in the state machine include user queries for feedback (such as feedback on a specific result or on a query in general) and user queries for state (for example, when a modified search may or may not be part of a new query, the user may be asked whether the user intended to continue the same query or start a new query.) 
   As stated above, in order to enable context-dependent evaluations of results of search mechanisms, context data is tracked. In one embodiment, this context data includes the state of the search, behavior data regarding the user&#39;s use of the browser  200  and, responses to user queries as to the intent of the user&#39;s behavior. Along with context data, user feedback data, either implicit or explicit, is also tracked. In one embodiment, user information is tracked. In this way, the user feedback can be used to evaluate the quality of the search mechanism in the context of the search performed. Additionally, relevance models can be evaluated as described above. 
   The state machine  225  works to detect the contours of a search session—when it starts, when it finishes, and what occurs during the search session. State machine  225  tracks the possible states of a search—when the user has finished the evaluation of the particular result, when the user is done with a particular query, and when questions need to be asked of users, such as what feedback the user has on a particular result item or on the query as a whole. Similar events which are detected by the browser helper object  210  may mean different things, depending on what stage of the search session has been arrived at. In order to track this, in one embodiment, state machine  225  is used to handle the complexity of search events yet maintain flexibility. The state machine design pattern is a common pattern which can be implemented, for example, as detailed in the popular “Gang of Four” book entitled  Design Patterns: Elements of Reusable Object-Oriented Software  (Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, Addison Wesley 1994.) Other implementations of state machine  225  are contemplated, as are other implementations of the user behavior tracer  220  which do not include a state machine. 
   Data Recording 
   As discussed above, for each search, three types of data are acquired by the data acquisition engine  230  through the user behavior tracer  220 . 
   (1) Context Data: This is data concerning the query or queries that the user used during the search. Context data can include data such as: the states of the search and associated timing, behavior data regarding the user&#39;s use of the browser  200  and responses to user queries as to the intent of the user&#39;s behavior. Generally context data allows user feedback data to be analyzed in the context of what was occurring leading to the feedback. 
   (2) Implicit User Feedback Data: This data reflects user behavior throughout the search session, such as page browsing, scrolling, clicking, and other user behavior. In one embodiment, timing information is also stored to describe the user behavior (As detailed above, as well as being used for implicit user feedback, data regarding user behavior is also used along with other data to drive transitions between the states in the state machine.) This user behavior data is not necessarily the raw user behavior data stream sent by the browser helper object  210 . In one embodiment, the raw data is interpreted and stored as four types of implicit user feedback data:
         a) user behavior while visiting a result list page, including the time spent at that result;   b) user behavior while exploring a hyper link on the result list page, such as a search tip link, including the time spent at that result;   c) user behavior for visiting a result item page, including the time spent at that result and other actions such as scrolling, printing or adding the document to the user&#39;s favorites;   (in one embodiment, the active time spent at the result is measured in these three cases by subtracting any time in which the browser has lost user focus, for example when a user switches to another application)   d) Result item ignore records the user behavior for ignoring a result item, i.e. when the user does not visit a result item though it appears as part of a result list.       

   These correspond to some extent to states in the state machine  225 , and the interpretation, in one embodiment, of raw data into interpreted user behavior data of these types occurs in the states of the state machine, while they are being traversed. 
   (3) Explicit User Feedback Data: This data is the explicit user feedback which has been requested about the result items the user visited and the query the user have submitted. For example, regarding a search, a query, or a specific result, the user may be asked, via a dialog box, “Did this answer your question?” and allowed to enter a response. As another example, regarding a specific result which the user ignored, the user may be asked “Why didn&#39;t you try this result?” and given choices including “I didn&#39;t think this would answer my question.” 
   User Information 
   In one embodiment, user information is gathered in addition to context data, implicit user feedback data and explicit user feedback data. The user&#39;s satisfaction may be dependent on certain qualities of the user. For example, if a user is using the search mechanism for work, as opposed to recreational use, the user may be less satisfied with a search mechanism that provides interesting but whimsical search results. On the other hand, a user using the search mechanism for fun may enjoy such results. Additionally, a user using a search mechanism via a slow connection to the search mechanism may be less satisfied with a larger-sized results page (for example, a results page with graphics or streaming audio or video) whereas a user using a fast connection may not have any loss of satisfaction due to a larger-results page. 
   In order to take into account user qualities in determining predicted user satisfaction, the user may be requested to provide certain user information. This user information is used as part of the context-based user feedback, along with context data, implicit user feedback data, and explicit user feedback data in order to evaluate predicted user satisfaction. 
     FIG. 3  is a flow diagram showing the process of gathering context-based feedback including user information according to one embodiment of the invention. In step  300 , used information is collected. In step  310 , the search mechanism is monitored for user behavior data regarding a search. In step  320 , the search mechanism is monitored for search mechanism response data regarding the search. While these steps  300 ,  310  and  320  are depicted as occurring in a specific order, they could be accomplished in parallel or in any order. The data is used to determine context-based user feedback data describing the search (step  330 ). 
   User feedback information, for example, may include information regarding the speed of the user&#39;s connection to the search mechanism; the type of the user&#39;s connection to the search mechanism; a classification of the user&#39;s use of the search mechanism; background information concerning the user; and the language which the user is using to perform the search. 
   Collecting Explicit Feedback 
   As discussed above, user dissatisfaction with the collection of explicit feedback data may lead users to stop using the search mechanism which collects such data, to be dissatisfied, or to input bogus data when explicit feedback data is requested. In order to prevent such user satisfaction and the resulting problems, explicit feedback is requested only in certain circumstances. 
     FIG. 4  is a flow diagram showing the process of gathering context-based feedback including explicit feedback according to one embodiment of the invention. In step  400 , the search mechanism is monitored for user behavior data regarding a search. In step  410 , the search mechanism is monitored for search mechanism response data regarding the search. In step  420  a determination is made as to whether explicit feedback data should be collected. If explicit feedback data should be collected, step  425 , such explicit feedback is gathered. While these steps  400 ,  410  and  420 / 425  are depicted as occurring in a specific order, they could be accomplished in parallel or in any order. Whether or not explicit feedback is collected, afterwards the data which is collected is used to determine context-based user feedback data describing the search (step  430 ). 
   One method to make the determination as to whether explicit feedback data should be collected in step  425  is to track snooze requests from users. The snooze request allows the user to respond to a request for explicit feedback by selecting a “snooze” option. The snooze request functions as a snooze button on an alarm clock does. The requests for explicit feedback are not made to the user while the snooze request is in effect. The snooze request may be in effect for a specific number of searches, or for a specific time period, or until the next time the user launches the search mechanism. 
   Another method of making the determination is to have a target value for how often explicit feedback should be requested. For example, explicit feedback may be requested for approximately only a certain percentage of searches or only a certain number of times per hour or per session. Different types of explicit feedback may be requested. Each different type of feedback may have a different target value. For example, explicit feedback regarding a search result which the user selected for further exploration may be requested 100% of the time. However, as described below, explicit feedback may also be requested for a search not selected by the user for further exploration. In the example, this type of explicit feedback on non-selected results may be requested only 20% of the time. Thus, the user experience can be adjusted and user satisfaction and data integrity can be enhanced. 
   Collecting Explicit Feedback on Non-Selected Results 
   In addition to determining the user&#39;s opinion of results selected by the user for further examination, it may be useful, in determining user satisfaction with a search, to determine why a user did not select a result. A user may have found the summary of the result presented to be adequate, or may have found the result to be inapposite or not the best result from among the search results. Collecting explicit feedback on non-selected results, therefore, may be useful in determining user satisfaction. These non-selected results may include non-standard results, such as weather forecasts, maps, or phone numbers which are displayed even where a user&#39;s search is directed towards, for example, web pages. 
   In one embodiment, explicit feedback is collected as to all non-selected results as a whole. In another embodiment, explicit feedback is collected as to one or more specific results which were not selected. In such an embodiment, the user may be presented with a dialogue box listing three non-selected results, with radio buttons for the user to select, for each non-selected result, from among a group of possible reasons that the non-selected results were not selected. For example, for each non-selected search result, the user may be asked to complete the sentence “You did not visit the following results because you . . . ” with one of three options: (1) “ . . . didn&#39;t think it would answer your question”; (2) “ . . . have been to this result before”; or (3) “ . . . didn&#39;t look at it.” Other possible options include (4) “ . . . could see the information I needed from the results page” or (5) “ . . . found a better result on the page.” 
     FIG. 5  is a flow diagram showing the process of gathering context-based feedback including explicit feedback on non-selected results according to one embodiment of the invention. In step  500 , the search mechanism is monitored for user behavior data regarding a search. In step  510 , the search mechanism is monitored for search mechanism response data regarding the search. In step  520  a determination is made as to whether explicit feedback data should be collected data should be collected. If explicit feedback data should be collected, step  525 , such explicit feedback is gathered, including explicit feedback data as to a non-selected result. While these steps  500 ,  510  and  520 / 525  are depicted as occurring in a specific order, they could be accomplished in parallel or in any order. Where or not explicit feedback is collected, afterwards the data which is collected is used to determine context-based user feedback data describing the search (step  530 ). 
   CONCLUSION 
   It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the invention has been described with reference to various embodiments, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitations. Further, although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein; rather, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. Those skilled in the art, having the benefit of the teachings of this specification, may effect numerous modifications thereto and changes may be made without departing from the scope and spirit of the invention in its aspects.