Pragmatic user model implementation in an intelligent help system

We present an intelligent help system for the Unix operating system called Aran. Aran is a passive, knowledge-based help system whose main goal is to help users deal with problems related to Unix operation. Aran gives the user access to different kinds of information, and it is designed to help the user accomplish a given task, while, at the same time, expanding the user's knowledge of the operating system. In order to accomplish its job Aran is endowed with an explicit representation of both domain specific knowledge and a pragmatic user model (UM) that takes into account the individual ́s characteristics. In Aran, user modeling is dynamic and based on stereotypes. The UM is implemented with the same representation environment, Loom, used in the rest of knowledge base (KB) modules. This environment is based on a description logics formalism that facilitates the construction and maintenance of all the modules.