The European GALEN project is developing terminology services based on a large, re-usable medical ontology. The ontology is being built using GRAIL, a description logic with transitivity and general concept inclusions.

Memento is a software infrastructure to support the construction and evolution of assistant applications (or assistants) that act as adjuncts to the human mind. Each assistant embodies an e ective understanding of some information domain or problem domain. The assistant employs this understanding to aid a user or user communityin the manipulation, transmission, and storage of meaningful information artifacts from the assistant's domain, called models. Additionally, models ow via the assistant's user interface at the semantic level. Memento provides mechanismswhich address all of these common assistant responsibilities. When combined, the mechanisms result in real{time artifact{based collaboration over an assistant's models. Memento preserves the meaning of an assistant's models throughout these processes by enforcementofthe domain's membership rules, called semantic constraints. Because Memento abstracts an assistant's models and semantic constraints, it is therefore said to be domain{ independent. Memento is composed of two layers. The bottom layer, described in Chapter 2,

This is a special online version of the thesis which omits much of the appendix section to decrease file size and facilitate quick download. Original contents of the appendix can still be viewed in the table of contents – omissions mostly regard scanned copies of data collection methods from industrial

One of the essential features of a software agent is its ability to cooperate with other software agents.