17.2 The Model of the User

The CYBERMAP offers not only a generic overview of the whole hyperdocument, but it shows a personalized view of the document based on the actual model of the user. This means that the system has to keep at least two knowledge bases about the user:

user profile:

The user profile contains data about the user's interests and preferences. This data is manipulated directly by the user and can be changed during the whole session.

reading history of the user:

The CYBERMAP has to show to users at least where they have been in the document. An advanced version of the system should also try to update the model of the user concerning user capabilities and user preferences by analyzing the reading behavior. The system would then be able to make better guesses about the interests of the reader.

The user model is of fundamental importance for a flexible and informative overview map. In our prototype implementations the user profile consists only of an interest list which is derived from the index. The user profile is used to reduce the number of nodes shown in the CYBERMAP. Only the nodes which are of interest to the user are shown in the hyperdrawers. The filtering is done by comparing the interest list with the contents of the nodes.

Following the taxonomy of chapter 2 we currently have an analytical cognitive, individual explicit user model with long-term capabilities where the user is in the agent role. An obvious extension to the interest list would be the integration of a thesaurus to reduce the number of entries in the index for the specification of the interest list. A more sophisticated user model would also try to analyze the reading behavior of the user in order to make guesses about other nodes which have not been specified in the user profile, but might be of potential interest to the reader. This means, that implicit capabilities would be added to the user model.