ERCIM News No.25 - April 1996

The Sherpa Project

by Francois Rechenmann

In various scientific domains, such as molecular biology, the important flow of experimental data leads to the design and the management of large knowledge bases. Four categories of knowledge can be identified: descriptive knowledge on the entities of the domains; behavioural knowledge on the dynamic behaviour of these entities; methodological knowledge on the methods which can be used to identify these entities and to complete their descriptions; terminological knowledge on the relationships between the names used in the knowledge base and the terms used in the domain.

The Sherpa project, at INRIA Rhône-Alpes, Grenoble, designs tools and models for knowledge representation. This work blends together the four kinds of knowledge through corresponding representation units: object-based representation; behavioural equations; task models; hypertext and lexicon. These categories of knowledge refer to each other through object references and URLs.

Knowledge bases can be used as Web servers whose skeleton is the structure of formal knowledge (mainly in the object-based formalism) and whose flesh consists of pieces of text and images tied to the objects. The advantage of such an approach are found in the consistency of the base (there are no dangling links since the skeleton is generated automatically) and the opportunity to build complex queries grounded on the formal knowledge (see figure). For instance, a user looking for an apartment in a real estate knowledge base can first select a filter form from the "house" concept, ask for the meaning of the slot/word "F3" to the lexicon and decide to fill the form with corresponding criteria; the user can select one of the objects provided as an answer and look at the ground map and a picture of the house together with the usual precise information. This combines the advantages of a very structured server with the freedom of the usual servers. A server on E. coli genome has been built with our previous work and we are involved in the production of a knowledge base on the fly (D. melanogaster) genome.

Since 1995, we have been working on the cooperative construction of knowledge bases for expressing the consensus between a community of geographically distributed people. Each researcher has a knowledge base from which knowledge can be isolated and submitted to the consensual knowledge base. The latter base will then contact the other members of the group for acceptation, rejection or comments on the submitted piece of knowledge. This raises problems of formal comparison and merging of contributions from several knowledge sources and of designing a robust protocol for such a task. A complete protocol has been designed for these activities.

The Sherpa Project in the World Wide Web:

Please contact:
Francois Rechenmann - INRIA
Tel: +33 7657 4777

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