The User Model in TAILOR

A user model refers to the knowledge a computer system has about the user. This knowledge affects both a system's behaviour and its communication with the user. TAILOR uses an explicit user model which can be defined as a system where knowledge about the user is explicitly represented and modifiable. Two criteria then are essential in such a user model. In order to decide whether a user can be classified as an expert, TAILOR has to determine;

a) the user's knowledge about specific items in the knowledge base

--> knowing the functionality of an object and the mechanical processes associated with it

b) knowledge about underlying concepts

--> understanding concepts which enable the workings of such objects

TAILOR thus defines an expert as a user who fulfils both criteria (a) and (b) and it is necessary to state that the user does not need to know about all objects in the knowledge base to be classified as an expert. His understanding of objects may be inferred from his understanding of other similar items. A naive user is then defined as one who neither understands the functionality or the underlying concepts of an object. Obviously, the categories of expert and naive are extremes and most users are somewhere in between.