Abstract:
A system and method is described for resolving a conflict detected while synchronizing a first data object in a first store associated with a mobile device and a second data object in a second store associated with a server. Once the conflict is detected, properties of the first data object are compared with corresponding properties of the second data object. If the properties and the corresponding properties that differ are designated as mergeable properties, the properties and the corresponding properties are merged. Merging the properties involves sending a preferred state associated with each of the properties and the corresponding properties to the mobile device and the server for updating the first data object and second data object, respectively, when an initial state for the properties and the corresponding properties is different than the preferred state. The preferred state is based on a likelihood that vital information would be lost if the preferred state did not replace the initial state of the property or the corresponding property. The merging is performed without user-intervention on the mobile device. In addition, the entire first data object or second data object is not sent to the mobile device to achieve the merge, thereby minimizing the data transfer to the mobile device.

Description:
[0001]     This application claims the benefit of application Ser. No. 09/892,676, filed Jun. 27, 2001, the benefit of the earlier filing date is hereby claimed under 35 U.S.C. §120. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates to synchronization between mobile devices and fixed devices, and, more specifically, to systems for resolving conflicts detected during a synchronization session between the mobile device and the fixed device.  
       BACKGROUND OF THE INVENTION  
       [0003]     Mobile devices, sometimes referred to as handheld devices, have become quite common today. The users of these mobile devices want to have their mobile device updated with current information quite frequently. The process for updating information involves communicating with a fixed device (i.e., server) and is commonly referred to as a synchronization session. Between synchronization sessions, the mobile device may change information in its mobile store and the fixed device may change information in its server store. If the information that is changed in the mobile store and the server store is associated with the same data object, a conflict is detected during the next synchronization session. In these situations, prior systems that synchronized data objects would provide some type of user interface on the mobile device that would indicate that the conflict existed and that the conflict was with a certain object. In one example, the device user would receive a notification regarding the conflict, when, in fact, the information changed on the object associated with the notification had identical information on both devices (i.e., both devices changed a last name field of a contact object from a maiden name to a married name). In addition to the unhelpful user interface that was provided, prior systems would also keep both versions of the data objects having the conflict on both the mobile device and on the fixed device. As one can imagine, keeping both objects wasted memory on the devices and caused extra work for the user to resolve the otherwise duplicate objects. In addition, sending the other version of the object used bandwidth on the data channel between the devices. Thus, there is a need for an improved method for resolving conflicts detected during a synchronization session that enhances the mobile user&#39;s experience.  
       SUMMARY OF THE INVENTION  
       [0004]     Briefly described, the present invention provides a method for resolving a conflict detected while synchronizing a first data object in a first store associated with a mobile device and a second data object in a second store associated with a server. In accordance with the present invention, certain conflicts are automatically resolved without requiring user-intervention on the mobile device and without duplicating data objects on either the mobile device or the server.  
         [0005]     In general, once a conflict is detected, properties of the first data object are compared with corresponding properties of the second data object. If the corresponding properties that differ are designated as mergeable properties, the corresponding properties are merged. Merging the properties involves sending a preferred state associated with each of the conflicting properties to the mobile device and the server for updating the first data object and second data object, respectively, when an initial state for the properties and the corresponding properties is different than the preferred state. The preferred state is based on a likelihood that vital information would be lost if the preferred state did not replace the initial state of the property or the corresponding property. For example, if a read property for an email object is marked as read on the mobile device and as unread on the server, the preferred state (unread) is sent to the mobile device to update the email object. Thus, a user is insured that if data is lost, the most conservative approach to data loss results, thereby reducing the danger of the data loss. The merging is performed without user-intervention on the mobile device. In addition, the entire first data object or second data object is not sent to the mobile device to achieve the merge, thereby minimizing the data transfer to the mobile device.  
         [0006]     In another aspect of the invention, a system for resolving a conflict detected during a synchronization session is provided. The system includes a first device, a second device, and a server. The first device is associated with a first data store that stores several data objects. The second device is associated with a second data store that stores several corresponding data objects. Each data object in the first data stores is associated with one of the corresponding data objects in the second data store. The server is configured to detect a conflict between the data objects and their corresponding data objects by determining whether a property of the data object is different than a corresponding property of the corresponding data object. If the property and the corresponding property are designates as mergeable properties, the server is configured to merge the property of the data object and the corresponding property. The merging is performed without user-intervention on the first device. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  illustrates an exemplary computing device that may be used in one exemplary embodiment of the present invention;  
         [0008]      FIG. 2  illustrates an exemplary mobile computing device that may be used in one exemplary embodiment of the present invention;  
         [0009]      FIG. 3  is a functional block diagram of one exemplary conflict resolution system as implemented using the computer device shown in  FIG. 1  and the mobile computing device shown in  FIG. 2 ;  
         [0010]      FIG. 4  is a graphical representation of one embodiment of the salient portions of a sample data object;  
         [0011]      FIG. 5  is a logical flow diagram generally illustrating an overview of a synchronization process with conflict resolution;  
         [0012]      FIG. 6  is a logical flow diagram illustrating a conflict resolution process suitable for use in  FIG. 5 ; and  
         [0013]      FIG. 7  is a logical flow diagram illustrating a user-selectable conflict process suitable for use in  FIG. 6 , in accordance with one embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]     The present invention may be implemented in one or more components operating within a distributed or wireless computing network. Those components may include software programs or applications operating on computing systems of various configurations. Two general types of computing systems are being used to implement the embodiments of the invention described here. Those two general types are illustrated in  FIG. 1  and  FIG. 2  and described below, followed by a detailed discussion of one illustrative implementation of the invention, illustrated in  FIGS. 3-7 , based on these two types of computer systems.  
         [0000]     Illustrative Operating Environment  
         [0015]     With reference to  FIG. 1 , one exemplary system for implementing the invention includes a computing device, such as computing device  100 . In a very basic configuration, computing device  100  typically includes at least one processing unit  102  and system memory  104 . Depending on the exact configuration and type of computing device, system memory  104  may be volatile (such as RAM), non-volatile (such as ROM, flash memory, etc.) or some combination of the two. System memory  104  typically includes an operating system  105 , one or more program modules  106 , and may include program data  107 . This basic configuration is illustrated in  FIG. 1  by those components within dashed line  108 .  
         [0016]     Computing device  100  may have additional features or functionality. For example, computing device  100  may also include additional data storage devices (removable and/or non-removable) such as, for example, magnetic disks, optical disks, or tape. Such additional storage is illustrated in  FIG. 1  by removable storage  109  and non-removable storage  110 . Computer storage media may include 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. System memory  104 , removable storage  109  and non-removable storage  110  are all examples of computer storage media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical 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 be accessed by computing device  100 . Any such computer storage media may be part of device  100 . Computing device  100  may also have input device(s)  112  such as keyboard, mouse, pen, voice input device, touch input device, etc. Output device(s)  114  such as a display, speakers, printer, etc. may also be included. These devices are well know in the art and need not be discussed at length here.  
         [0017]     Computing device  100  may also contain communication connections  116  that allow the device to communicate with other computing devices  118 , such as over a network. Communications connections  116  is one example of communication media. Communication media may typically be embodied by 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. The term computer readable media as used herein includes both storage media and communication media.  
         [0018]     With reference to  FIG. 2 , one exemplary system for implementing the invention includes a mobile computing device, such as mobile computing device  200 . The mobile computing device  200  has a processor  260 , a memory  262 , a display  228 , and a keypad  232 . The memory  262  generally includes both volatile memory (e.g., RAM) and non-volatile memory (e.g., ROM, Flash Memory, or the like). The mobile computing device  200  includes an operating system  264 , such as the WINDOWS CE brand operating system from MICROSOFT CORPORATION located in Redmond, Wash., or other operating system, which is resident in the memory  262  and executes on the processor  260 . The keypad  232  may be a push button numeric dialing pad (such as on a typical telephone), a multi-key keyboard (such as a conventional keyboard). The display  228  may be a liquid crystal display, or any other type of display commonly used in mobile computing devices. The display  228  may be touch sensitive, and would then also act as an input device.  
         [0019]     One or more application programs  266  are loaded into memory  262  and run on the operating system  264 . Examples of application programs include phone dialer programs, email programs, scheduling programs, PIM (personal information management) programs, word processing programs, spreadsheet programs, Internet browser programs, and so forth. The mobile computing device  200  also includes non-volatile storage  268  within the memory  262 . The non-volatile storage  268  may be used to store persistent information which should not be lost if the mobile computing device  200  is powered down. The applications  266  may use and store information in the storage  268 , such as e-mail or other messages used by an e-mail application, contact information used by a PIM, appointment information used by a scheduling program, documents used by a word processing application, and the like. A synchronization application also resides on the mobile computing device  200  and is programmed to interact with a corresponding synchronization application resident on a host computer to keep the information stored in the storage  268  synchronized with corresponding information stored at the host computer.  
         [0020]     The mobile computing device  200  has a power supply  270 , which may be implemented as one or more batteries. The power supply  270  might further include an external power source, such as an AC adapter or a powered docking cradle, that supplements or recharges the batteries.  
         [0021]     The mobile computing device  200  is also shown with two types of external notification mechanisms: an LED  240  and an audio interface  274 . These devices may be directly coupled to the power supply  270  so that when activated, they remain on for a duration dictated by the notification mechanism even though the processor  260  and other components might shut down to conserve battery power. The LED  240  may be programmed to remain on indefinitely until the user takes action to indicate the powered-on status of the device. The audio interface  274  is used to provide audible signals to and receive audible signals from the user. For example, the audio interface  274  may be coupled to a speaker for providing audible output and to a microphone for receiving audible input, such as to facilitate a telephone conversation.  
         [0022]     The mobile computing device  200  also includes a radio interface layer  272  that performs the function of transmitting and receiving radio frequency communications. The radio interface layer  272  facilitates wireless connectivity between the mobile computing device  200  and the outside world, via a communications carrier or service provider. Transmissions to and from the radio interface layer  272  are conducted under control of the operating system  264 . In other words, communications received by the radio interface layer  272  may be disseminated to application programs  266  via the operating system  264 , and vice versa.  
         [0000]     Illustrative Conflict Resolution System  
         [0023]      FIG. 3  is a functional block diagram generally illustrating one embodiment for a synchronization system with conflict resolution  300  that resolves conflicts between data objects detected during a synchronization session between a fixed computing device, such as an information server  310  and a mobile device  320 , in accordance with the present invention. In this implementation, the information server  310  is a computing device such as the one described above in conjunction with  FIG. 1 , and the mobile device  320  (i.e., client) is a mobile computing device such as the one described above in conjunction with  FIG. 2 . A synchronization application  342  performs the synchronization process between the information server  310  and the mobile device  320 . The synchronization application  342  includes a conflict manager  380  for detecting and resolving the conflicts during the synchronization sessions. In the embodiment illustrated, the synchronization application  342  resides on a synchronization server  340 , which is a computing device as described above in conjunction with  FIG. 1 . Alternatively, the synchronization application  342  may reside in any acceptable location, such as directly on the information server  340  or on the mobile device  320 . The synchronization server  340  is shown coupled to the information server  310  over a local or wide area network in the conventional manner. In another embodiment, the synchronization application  342  may reside on information server  310  without departing from the scope of the present invention.  
         [0024]     The mobile device  320  maintains mobile data  322  (i.e., a mobile data store) locally in its non-volatile storage  268  (shown in  FIG. 2 ). Information server  310  maintains server data  312  (i.e., a server data store) on its removable storage  109  or non-removable storage  110  (shown in  FIG. 1 ). As mentioned earlier, the mobile data  322  and the server data  312  may include e-mail or other messages used by an e-mail application, contact information used by a PIM, appointment information used by a scheduling program, and the like. Typically, each type of data in the mobile data  322  or server data  312  is referred to as a “collection” (e.g., e-mail and contacts are two separate collections). Each collection includes a plurality of data objects. For example, the server data  312  includes a plurality of server data objects  314  and the mobile data  322  includes a plurality of mobile data objects  324 . A representative illustration of the salient portions of a sample data object is illustrated in  FIG. 4  and described below.  
         [0025]     The mobile device  320  may change the mobile data  322  on the mobile device  320  at anytime. Once the mobile data  322  is changed, server data  312  accessible by the information server  310  will not have identical information. Similarly, the information server  310  may change the server data  312 , such as through any number of networked personal computers (not shown) connected to the information server  310 . Again, once the server data  312  is changed, the mobile data  322  and server data  312  are no longer identical (i.e., data is not synchronized and the changes on both sides create a conflict). In order for the mobile data  322  and the server data  312  to become identical (i.e., synchronized), typically, the mobile device  320  initiates a synchronization session. During the synchronization session, the synchronization application  342  attempts to update the server data objects  314  and the mobile data objects  324  to have identical information. In other words, after a successfully synchronization session, the server data objects  314  will have a corresponding mobile data object  324  with the same information.  
         [0026]     Briefly, during the synchronization session of one embodiment of the present invention, client synchronization data  330  is transmitted between the mobile device  320  and the synchronization application  342 , and server synchronization data  350  is transmitted between the synchronization application  342  and the information server  310 . The client synchronization data  330  specifies changes to the mobile data  322  since the last successful synchronization session and specifies changes to the server data  312  that the mobile device  320  should update on its mobile data  322 . The server synchronization data  350  specifies changes that the information server  310  should make to its server data  312  and specifies changes to the server data  312  that the mobile device  320  should make to its mobile data  322 . The synchronization application  342  saves information regarding the synchronization session in a synchronization state table  344 .  
         [0027]     During the synchronization sessions, the conflict manager  380 , briefly described here and illustrated in  FIGS. 5-7  and described in detail below, determines which of the changes to the mobile data  322  and the server data  312  involve a conflict. After determining there is a conflict, the conflict manager  380  attempts to resolve the conflict without sending a conflict notification  382  to the mobile device  320 . In one embodiment, the client synchronization data  330  includes a parameter  332 , described in more detail with reference to  FIGS. 6 and 7 , that specifies how automatic conflict resolution should be handled. However, when certain types of conflicts occur, a conflict notification  382  is sent to the mobile device  320 . A sample XML message is shown below that represents a general format for one embodiment of the conflict notification  382  sent to the mobile device  320 .  
                                                                                                               &lt;SYNC&gt;                ...           &lt;COLLECTION&gt;                &lt;COLLECTIONTYPE&gt;E-MAIL&lt;/&gt;           &lt;RESPONSES&gt;                &lt;RESPONSE&gt;                &lt;OBJECT ID&gt;123&lt;/&gt;           &lt;COMMAND&gt;CHANGE&lt;/&gt;           &lt;STATUS&gt;READ FLAG MODIFIED&lt;/&gt;           &lt;/&gt;                &lt;/&gt;           ...                &lt;/&gt;                      
 
         [0028]     As shown, the sample conflict notification includes the object id (shown as “123”) that has changed and a status (shown as “Read Flag Modified”) describing the type of change that occurred. In general, the conflict notification  382  provides sufficient information to the mobile device  320  such that the mobile device  320  may provide a suitable user interface (not shown) to the user regarding the conflict. The user interface may be implemented in any manner and will depend on how the application  266  (shown in  FIG. 2 ) responsible for displaying the conflict information chooses to relay the conflict information to the user of the mobile device  320 . Because the specific user interface chosen is not pertinent to understand the present invention, the present discussion does not further describe the user interface on the mobile device  320 . The sample conflict notification shown above only includes the property that caused the conflict than the entire object. This embodiment increases the efficiency of the conflict resolution process when using wireless technology because less data is sent.  
         [0029]     As will be described in greater detail below, the conflict manager  380  in accordance with the present invention, automatically resolves certain conflicts and provides sufficient conflict notification  382  to the mobile device  320  for a user to select how the conflict should be resolved using the user interface on the mobile device  320  when the conflict can not be automatically resolved. Thus, the present invention provides an efficient method for resolving conflicts in data objects during a synchronization session.  
         [0030]      FIG. 4  is a graphical representation of one embodiment of the salient portions of a sample data object  400  that may be used as a server data object  314  or a mobile data object  324  in conjunction with present invention. The sample data object  400  includes an object id (OID)  402 , a plurality of properties P 1-N , and a change indicator  404 . The object id  402  may be a server ID (SID) if the object ID (OID) is stored on the server  310  or a device ID (DID) if the object ID is stored on the device  320 . As one skilled in the art will appreciate, after synchronization is complete, each SID typically has a corresponding DID on the mobile device to which it is mapped. The properties P 1-N  store information associated with the data object based on the type of data object.  
         [0031]     A representative data object is illustrated in  FIG. 4  and represents an email message object. The illustrative properties for the email message object may include a recipient field P 1 , a sender field P 2 , a read flag field P 3 , a message text field P 4 , a subject field P 5 , a data last read field P 6 , a priority field P 7 , a follow-up flag field P 8  and any other information regarding the email message object. The change indicator  404  indicates when any the properties P 1-N  of the data object  400  have changed. For example, if a user reads the email message, property # 4  (read property) is set to indicate read and the change indicator  404  is marked indicating that the data object  400  has changed in some way. When the change indicator  404  is so marked, the data object  400  is sometimes referred to as “dirty”. The data object  400  is considered “dirty” even if the user reads the email message and then sets the email message as unread (the value of property # 4  would, in essence, remain the same).  
         [0032]     In accordance with the present invention, certain properties are also designated as syncable properties  406 . Syncable properties  406  are properties within the data object  400  that may be changed. Typically, properties that cannot be changed are not designated as syncable properties (e.g., the recipient field P 1  and the sender field P 2 ). However, these non-changeable properties may be designated as syncable properties without departing from the scope of the present invention. In addition, in accordance with the present invention, some of the designated syncable properties  406  are further designated as mergeable properties  408  (e.g., the read property P 3 ). As will be described in detail below in reference to  FIGS. 5-7 , the conflict manager uses the change indicator  404 , the syncable properties  406  and the mergeable properties  408  when determining a “true” conflict and resolving the “true” conflict, in accordance with the present invention. By determining “true” conflicts in the manner described in the present invention, users do not receive unhelpful conflict messages and do not need to intervene each time both the mobile data object and the corresponding server data change.  
         [0033]      FIG. 5  is a logical flow diagram generally illustrating an overview of a synchronization process having a conflict resolution process for resolving conflicts detected during a synchronization session. Briefly, the overview of the synchronization process shown in  FIG. 5  detects whether a potential conflict, in accordance with the present invention, may exist and the manner in which the potential conflict is resolved during the synchronization process. The synchronization process with conflict resolution  500  begins at block  501 , where a synchronization session has been initiated and both the mobile device  320  and the information server  320  have sent client synchronization data  330  and server synchronization data  350  to the synchronization application  342 , respectively. The synchronization application  342  has passed the client synchronization data  330  and server synchronization data  350  to the conflict manager  380  for conflict processing. Processing continues at blocks  502  and  504 .  
         [0034]     At blocks  502  and  504 , the conflict manager  380  gets one of the mobile data objects  324  (block  502 ) and a corresponding server data object  314  ( 504 ).  
         [0035]     At block  506 , the conflict manager  380  checks the change indicator  404  associated with the corresponding server data object  314  to determine whether any changes have been made to the server data object  314 .  
         [0036]     At decision block  508 , if the change indicator  404  associated with server data object  314  indicates that the server data object  314  is not “dirty” (i.e., no changes were made to any properties associated with the server data object  314 ), the process continues at block  510 .  
         [0037]     At block  510 , the conflict manager  380  checks the change indicator  404  associated with the mobile data object  324  to determine whether any changes have been made to the mobile data object  324 .  
         [0038]     At decision block  512 , if the change indicator  404  associated with the mobile data object  324  indicates that the mobile data object  324  is not “dirty” (i.e., no changes were made to any properties associated with the mobile data object  324 ), the mobile data object  324  and the server data object  314  are not synchronized because neither data object had updates. In one embodiment, either the mobile data object  324  or the server data object  314  will be “dirty”. This reduces the amount of data transmitted in the synchronization data because it insures at least one of the data objects has changed. If the mobile data object  324  is not “dirty” at decision block  512 , processing continues at decision block  514 .  
         [0039]     At decision block  514 , the conflict manager  380  determines whether there are any more mobile data objects  324  and corresponding server data objects  314 . If some data objects  314 ,  324  still remain to be processed, the process loops back to block  502  and proceeds as described above. However, once all the data objects  324   314  have been processed, the conflict resolution processing within the synchronization process is complete and the process ends at end block  516 .  
         [0040]     Now, returning to decision block  508 , if the conflict manager  380  determines that the server data object is “dirty”, processing continues at block  518  and then to decision block  520 . At block  518 , the conflict manager  380  checks the change indicator  404  associated with the mobile data object  324  to determine whether any changes have been made to the mobile data object  324 . At decision block  520 , if the change indicator  404  associated with the mobile data object  324  indicates that the mobile data object  324  is not “dirty” (i.e., no changes were made to any properties associated with the mobile data object  324 ). If the mobile data object  324  is not “dirty”, this indicates that only one of the data objects is “dirty”. Thus, the data objects  314   324  may be synchronized using any well-known synchronization technique without performing the conflict resolution process of the present invention. Typically, the synchronization provided in block  522  attempts to update both data objects  314   324  to have identical information. Block  522  is also entered after a determination is made at decision block  512  that only the mobile data object  324  is “dirty”. Again, because only one of the data objects is “dirty”, synchronization is provided without performing the conflict resolution process of the present invention.  
         [0041]     However, if both data objects  314   324  are “dirty”, as determined at decision blocks  508  and  520 , processing continues to block  524 . Briefly, at block  524 , the conflict manager determines the extent of the conflict between the mobile data object  324  and the server data object  314  and attempts to resolve the conflict with as little user intervention as possible. A detailed description of the conflict resolution process is illustrated in  FIG. 6  and described below. Processing then continues to decision block  514  and proceeds as described above.  
         [0042]      FIG. 6  is a logical flow diagram illustrating one embodiment of a conflict resolution process  600  suitable for use in  FIG. 5 . The conflict resolution process  600  begins at block  601 , after the conflict manager  380  has determined that there is a conflict between a mobile data object  324  and a corresponding server data object  314 . Processing continues at decision block  602 .  
         [0043]     At decision block  602 , a determination is made whether the change indicator  404  indicates that the server data object  324  was “dirty” because the server data object  314  has been deleted. If the server data object  314  has been deleted, processing continues to block  604 . At block  604 , the conflict manager instructs the synchronization application  342  ( FIG. 3 ) to delete the corresponding mobile data object  324 . The synchronization application  342  may then include the appropriate information in the client synchronization data  330  sent to the mobile device  320  at some later time. The synchronization application may include the information in the current synchronization session or in a later synchronization session. Processing continues to return block  606  and back to  FIG. 5 .  
         [0044]     Returning back to decision block  602 , if the server data object  314  has not been deleted, processing continues to decision block  608 . At decision block  608 , a determination is made whether the change indicator  404  for the mobile data object  324  indicated that the mobile data object  324  was “dirty” because the mobile data object  324  has been deleted. If the mobile data object  324  has not been deleted, processing continues at block  610 . At block  610 , the conflict manager instructs the synchronization application  342  ( FIG. 3 ) to delete the corresponding server data object  314  during one of the synchronization sessions. Processing continues to return block  606  and back to  FIG. 6 .  
         [0045]     Returning back to decision block  608 , if the mobile data object  324  has not been deleted, processing continues at block  612 . At block  612 , the properties of the mobile data object  324  and the server data object  314  that were designated as syncable properties are compared. As mentioned earlier, by specifying only certain of the properties as syncable properties  406 , the present invention decreases the number of conflicts that are reported compared to prior conflict resolution methods. In addition, the conflict resolution process, in accordance with the present invention, is able to automatically resolve these “true” conflicts based on the syncable properties without user intervention in certain situations. Processing continues to decision block  614 .  
         [0046]     At decision block  614 , a determination is made whether any of the syncable properties indeed differ. If none of the syncable properties differ, processing continues to block  616 , where the change indicator  404  for both the mobile data object  324  and the server data object  314  are reset to indicate that the corresponding object is not “dirty.” Thus, in accordance with the present invention, the user of the mobile device  320  does not receive an unintelligible conflict message due to changes in the data objects  314   324  that do not warrant user concern. For example, if only the “Read” property has been changed from unread to read on both objects, even though both messages are “dirty,” the information is the same and the user need not be informed. Processing continues to return block  606  and back to  FIG. 6 .  
         [0047]     Returning back to decision block  614 , if it is determined that syncable properties differ, processing continues to decision block  618 , where the syncable property is retrieved.  
         [0048]     At block  620 , a determination is made whether all the syncable properties that differ can be resolved using the simple merge process. This determination is based on whether the syncable properties that differ are also designated as mergeable properties  408  ( FIG. 4 ) in the data objects. If any of the syncable properties that differ are designated as a mergeable property, the process continues at block  624 .  
         [0049]     At block  624 , a simple merge process is performed. In accordance with the present invention, each property designated as a mergeable property has an associated pre-determined preferred state for the property. In one embodiment, the preferred state is related to the likelihood that vital information would be lost if the property of the data object was not changed to the preferred state. In another embodiment, the user on the mobile device may specify the preferred state for the property designated as a mergeable property. During the simple merge process the preferred state for the property is pushed to the data object with the property in a state different than the preferred state. A beneficial effect on resolving the conflict using the simple merge process is that the user is not inconvenienced by an unintelligible conflict message that requires user-intervention and that the user does not lose vital information. Below are two tables summarizing the outcome of processing from block  624 . Table 1 summarizes the simple merge process (block  624 ) for conflicting email objects in which “UNREAD” is the preferred state. Table 2 summarizes the simple merge process (block  624 ) for conflicting appointment objects in which “POSTPONE” or “POSTPONE to earliest time” is the preferred state.  
                                                             TABLE 1                           Starting State   User Action   State After Change   Simple Merge Changes       (Synched)   (Disconnected)   (Disconnected)   (N/C = No Change)            Server   Device   Server   Device   Server   Device   Server   Device               READ   READ   Marks Mail   Marks Mail As   UNREAD   READ   UNREAD, N/C   Change to UNREAD;               As UNREAD   UNREAD, then               Send conflict                   READs mail               status to device       READ   READ   Marks Mail As   Marks Mail As   READ   READ   READ, N/C   READ, N/C               UNREAD, then   UNREAD, then               READs it   READs it       READ   READ   Marks Mail As   Marks Mail   READ   UNREAD   Change to   UNREAD, N/C               UNREAD, then   As UNREAD           UNREAD               READS it       UNREAD   UNREAD   READs mail, then   READs Mail   UNREAD   READ   UNREAD, N/C   Change to UNREAD;               Marks As UNREAD                   Send conflict                                   status to device       UNREAD   UNREAD   READs mail, then   READs mail, then   UNREAD   UNREAD   UNREAD, N/C   UNREAD, N/C               Marks As UNREAD   Marks As UNREAD       UNREAD   UNREAD   READs Mail   READs mail, then   READ   UNREAD   Change to   UNREAD, N/C                   Marks As UNREAD           UNREAD                  
 
         [0050]                                                      TABLE 2                           Starting State   User Action   Simple Merge Action Performed       (Synched)   (Disconnected)   (N/C = No Change)            Server   Device   Server   Device   Server   Device               Reminder ON   Reminder ON   Dismiss   Dismiss   N/C   N/C       Reminder ON   Reminder ON   Dismiss   Postpone for   Change to   N/C                   X minutes   Postpone for                       X Minutes       Reminder ON   Reminder ON   Postpone for   Dismiss   N/C   Change to Postpone               X minutes           for X Minutes; send                           conflict property to                           device       Reminder ON   Reminder ON   Postpone   Postpone   N/C   N/C               until X:00.   until X:00.       Reminder ON   Reminder ON   Postpone   Postpone   Sync the change   Sync the change that               until X:00.   until Y:00.   that reminds the   reminds the user the                       user the earliest.   earliest; send                           conflict property to                           device.                    
 After the simple merge process is completed, processing continues at block  626 . 
 
         [0051]     At block  626 , a conflict notification for the above syncable property is prepared. As described earlier, the conflict notification provides sufficient information that the mobile device  320  may display a user interface with the information if desired. In one embodiment, only the property causing the conflict is sent to the mobile device rather than the entire data object. Processing continues to return block  606  and back to  FIG. 5 .  
         [0052]     Returning to decision block  620 , when all the syncable properties that differ cannot be resolved using a simple merge process, processing continue to block  622 . At block  622 , a user-selectable conflict resolution process is performed based on a conflict resolution method selected by the user of the mobile device  320 . Briefly, in one embodiment, a user may request one of three conflict resolution methods: client wins, server wins, or keep both. The user of the mobile device  320  selects the method using one of the input devices  112  available on the mobile device, such as a keypad. The appropriate program module  106  will then include the parameter  322  that specifies the selected method within the synchronization data  330  sent to the synchronization application  342 . The synchronization application  342  will provide the parameter  332  to the conflict manager  380 . The technique used to specify the selected method for conflict resolution and pass the information to the conflict manager  380  may be achieved using various techniques known with the art and which do not involve undue experimentation. The user-selectable conflict resolution is illustrated in  FIG. 7  and described below in detail. Processing continues to return block  606  and back to  FIG. 5 .  
         [0053]      FIG. 7  is a logical flow diagram illustrating one embodiment of a user-selectable conflict process  700  suitable for use in  FIG. 6 . The user-selectable conflict resolution process  700  begins at block  701 , after there has been a determination that a simple merge process is not available for resolving the conflict between the mobile data object  324  and the corresponding server data object  314 . Processing continues at decision block  702 .  
         [0054]     At block  702 , a determination is made whether the user of the mobile device  320  chose the “client wins” method. If the “client wins” method was chosen, processing continues at block  704 . At block  704 , the server data object  314  is replaced with the mobile data object  324 . One skilled in the art will appreciate that the replacement of the data object may occur immediately or at some later time during the synchronization session or a later synchronization session. Processing continues to return block  718  and back to  FIG. 6 .  
         [0055]     Returning to block  702 , if the user did not chose the “client wins” method, processing continues to decision block  706 . At decision block  706 , a determination is made whether the user selected the “server wins” method. If the “server wins” method is chosen, processing continues to blocks  708  and  710 . At block  708 , a copy of the server data object  314  is sent to the mobile device  320 . At block  710 , the mobile data object  324  is replaced with the server data object  314 . Again, the actual replacement of the mobile data object  324  may occur at anytime during the synchronization session or may occur during a later synchronization session. Processing continues to return block  718  and back to  FIG. 6 .  
         [0056]     Returning to block  706 , if the user did not chose the “server wins” method, the default method “keep both” is performed. Processing continues at blocks  712 - 714 . At block  712 , a copy of the server data object  314  is sent to the mobile device  320 . At block  714 , the prior mobile data object  324  is sent to the server as a new data object during the next synchronization session. Processing continues to return block  718  and back to  FIG. 6 .  
         [0057]     The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.