Troeps knowledge servers

Experimental server of the Exmo team

Executive summary: Co4 is an environnement enabling a group of geographically distributed users to build together a knowledge base accessible through the worldwide web. This is applied to scientific knowledge base construction (in genomics) and corporate memories (in micro-electronics). To that extent, the object-based knowledge representation system Troeps can be turned into a knowledge server allowing to browse, query and edit structured knowledge. This knowledge is also linked to informal text, pictures, a lexicon and other web sites. The collaboration between users is managed by a protocol which warrants that common knowledge bases are consistent and consensual. The protocol is implemented as library that can be used for other applications which aim is the collaborative construction of an artefact.

Direct access to information:
XML experiments

K. servers version 1.3: Knife | S. T. and G. | Coligene (local) | Real estate | Launch the server

Workplan and achievements: Our research objective (until year 2000) was the complete design and experimentation of an environnement enabling a group of geographically distributed users to build together a knowledge base accessible through the worldwide web. During the 1995-1997 period, our knowledge base management system Troeps has been made available to the Web (knowledge server part) and the theoretical foundations for concurent modification of the knowledge has been laid out (Co4 protocol and work on knowledge base revision). Then (1998-1999), the Co4 protocol has been implemented, verified and connected to the Troeps knowledge servers. The system has been experimented for internal use and delivered to a couple of sites.

Knowledge servers: knowledge base browsing and editing through the Web

Troeps knowledge servers allow to use Troeps as a HTTP server instead of a knowledge base system. Then, anyone can browse and edit the knowledge base with the help of a HTTP client (such as Mosaic or Navigator or Explorer). [o] is a review of related projects worldwide.

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.

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 texts and images tied to the objects (see [Euzenat1996a]). The advantages of such an approach are found in the consistency of the base (there are no dangling link 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 given as answers and have a 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 usual servers. This participates in the Knowledge medium idea promoted by Mark Stefik and can be called an "intelligence added" web server. A server on E. coli genome has been built with our previous work and we are involved in the craft of a knowledge base on the fly (D. melanogaster) genome.

A sample query session

The Troeps knowledge bases are both browsable and editable through the World-wide web (though the knowledge bases below are in read-only mode). The graphic user interface is still the same but allows the user to create, modify or destroy the objects and the conceptual scheme of the knowledge base.
Editing raises problems of consistency and concurent access to the base. This is the subject of the Co4 line of our work.

You can consult the following knowledge bases:

Technical details can be found here.

Co4: Cooperative construction of consensual knowledge bases

The cooperative construction of knowledge bases aims at expressing the consensus between a community of geographically distributed people. We also plan to use Co4 and its architecture in corporate memory applications.
The purpose of Co4 is the building of knowledge bases which are:
since everything in the base has been accepted by the people involved in the construction;
Cooperatively constructed
since people cooperates in order to build the knowledge base;
since they are stored under a formal repository of knowledge (and checked for consistency);
The last Co
stands for connaissance (knowledge).
Co4 depends upon a simple architecture of related knowledge bases and a formal protocol for submitting and discussing knowledge which is freely inspired from those used in scientific journals. The principles of Co4 are as follows: Each researcher has a knowledge base (browsable through a knowledge server) from which knowledge can be isolated and submitted to the consensual knowledge base (called group 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 relevant paper is [Euzenat1995a].

A complete protocol has been designed for these activities. Its description can be found in [Euzenat1997a]. A demonstration is also available on video.
It has been expressed into LOTOS and checked for various kinds of deadlocks.
It has been implemented into a UNIX library [Sherpa1998] and is now freely available. For the communication, the KQML application programming interface from EIT (Lockheed) is used. It has been extended towards asynchronous message transmission.

Updated by Jerome . Euzenat À inrialpes . fr on 20/4/2003