Modeling a User's Domain Knowledge

In an AHS the domain model consists of a set of concepts. The user learns about concepts by reading about them and/or by taking tests or performing assignments. There can be a one-to-one correspondence between concepts and nodes (a "fine grained" approach), but a single concept may also correspond to a large set of nodes (a "course grained" approach). Different techniques (value sets) are used to model a user's knowledge about a concept: Apart from knowledge per se most systems also log some navigation history information as well. So about each concept not only a knowledge-value may be known but also some information as to how the user obtained that knowledge. (For each node the access times may be stored for instance.) In general one may assume that for each concept an AHS stores a number of attribute values, of which the knowledge-value is only one.