User Modeling for the Mars Medical Assistant MCS Project By Mihir Kulkarni

The Presentation n User Modeling (UM) n The Mars Medical Assistant n User Modeling in the context of MMA

User Modeling n Definition: –A technique for constructing an explicit representation of the user. n Advantages: –Allows adaptation of the system behavior –Improves capabilities to understand and process user requests. –Improves usability of the system

Classification of UM n User Models can be classified based on 3 criteria: –Granularity –Temporal Extent –Representation of user knowledge.

Tasks involved in UM 1. Acquisition of User Model –Explicitly: specified by the users or the system designer. –Implicitly: inferred on the basis of user’s behavior and interactions with the system.

Tasks involved in UM 2. Representation of User Model Depends on the type of application being developed.Depends on the type of application being developed. Some common representations:Some common representations: n Scalar or parametric n Hierarchical representations n Stereotypes

Challenges of user representation n Noisy data n User change n Dialog reliability n Current research targeted in developing new approaches –E.g.) UMT, BGP-MS etc.

Mars Medical Assistant n MMA –An Adaptive Hypermedia System –Plays the role of an Assistant in delivery of medical information n Goal –Facilitate the medical task by providing the medic access to large amount of medical information

Mars Medical Assistant n How is information provided? –Medical information is divided and categorized into n Semantic content n Cognitive characteristics of media type –Information Components are created based on the semantic and media type –Information is provided to the medic through the appropriate Information Components.

Mars Medical Assistant n Adaptation in MMA: –What to show? n Topic n Level of detail n Point of view –How to show it? n Selection of media type n Sorting of IC’s n Visibility of IC’s

Mars Medical Assistant n Conflict Resolution in MMA Content Suggestions Presentation suggestions Information User Model Task Model Situation Model Browser Presentatio n Service Content Service Conflict resolutio n Negotiation and Conflict resolution Requests Conflict resolution

User Modeling in MMA n MMA used by –different users in different situations to accomplish different tasks. –supports diverse users with varying roles, expertise and level of proficiency n considering the relevant characteristics of the user allows for profitable adaptation of the system.

User Modeling in MMA n The User Model includes information about an individual’s knowledge about each –Medical topic –Medical profile –Preferences

User modeling in MMA n The User Model in MMA consists of 3 parts: –Medical History Model –Medical Expertise Model –Preference Model

User Modeling in MMA n Medical History Model –Provides the MMA information related to the medical history of the user. –Composed of 2 parts: n Medical Profile n Medical history –API provided to retrieve information from the model based on different parameters.

User Modeling in MMA n Medical Expertise Model –Contains information n about an user’s expertise in each medical skill n training required or not n Number of times skill used –Helps the MMA in adapting the level of detail in the information provided to the medic. –API provided to retrieve information from the model based on different parameters.

User Modeling in MMA n Preference Model –Contains information about the preferred media type and semantic type –The model contains an ordering of the preferences for each task in each situation for each medical topic –Helps the MMA in adapting the order and visibility of the Information Components.

User Modeling in MMA n Adaptation based on Preference Model –based on the time spent by the user in each media type. –higher Preference given to the media type where the user spends the most time. n Assumption made by the inference mechanism : –if a user does not think a media type, he/she selected to be suitable, he/she would switch to another media type.

User Modeling in MMA n Will the assumptions made by the inference mechanism cause harm ? –Probably not !!! –Why ? Because the preference order has just been suggested by the system –The User still retains the right, to override the system’s suggested preference order.

User Modeling in MMA n The User Modeling Prototype –a fine-grained model has been developed for each user. –models have been developed independent from the MMA application. –an API is provided to store and retrieve information.

User Modeling in MMA n The User Modeling Prototype –developed as a Java application. –Uses text files for storing information about the users in a structured way.

User Modeling in MMA n Conclusions: –The User Model developed for the MMA emphasizes the importance of User Modeling in the development of Adaptive Interface System.