The justified user model: A viewable explained user model

This paper describes our experiences with giving users access to the system’s model of them. This access is supported by a number of tools that enable a user to see various forms of information: an overview display serves as a navigation tool as well as a helpful summary; the main model viewer program enables the user to see the detailed model the system holds; the justification part explains the system’s reasoning about the user model; the explanation subsystem provides a tailorable glossary of the terms used in the user model description; and the change facility allows the user to add their view of the correct value of components of the model. We outline the series of studies we have conducted to learn how users respond to our visual displays of a user model. These indicate a new purpose for a user model as a useful communication tool that enables users to find information that interests them as well as to communicate the way that they would like to be modelled. We also discuss some issues that arise from making the user model accessible. These affect the way that the programmer sees their relationship to the user. They also highlight the need to address different interpretations of a user model.