This article-is a survey of some methods, techniques and tools aimed at managing corporate knowledge from a corporate memory designer's perspective. In particular, it analyses problems and solutions related to the following steps: detection of needs of corporate memory, construction of the corporate memory, its di!usion (specially using the Internet technologies), use, evaluation and evolution

With the aim of building a "Semantic Web", the content of the documents must be explicitly represented through metadata in order to enable contents-guided search. Our approach is to exploit a standard language (RDF, recommended by W3C) for expressing such metadata and to interpret these metadata in conceptual graphs (CG) in order to exploit querying and inferencing capabilities enabled by CG formalism. The paper presents our mapping of RDF into CG and its interest in the context of the semantic Web 1 .

NO MATTER WHO USES A CORporate memory or how it is constructed, information search through that memory should be efficient and effective. In particular, it should adapt to the users' needs, activities, and work environments. For a document-based corporate memory distributed through the Web, which is our research area, these requirements raise two main questions: How will we describe the documents that will be part of this corporate memory? How can we improve their retrieval on the Web, particularly by taking advantage of knowledge models? To answer these questions, we've developed a strategy that applies the XML (Extensible Markup Language) metalanguage to knowledge management for an enterprise. (In this case, an enterprise is an actual company or a virtual enterprise made of distributed organizations and teams of people who work together online.) We've implemented this strategy in the Osirix (ontology-guided search for information retrieval in XML documents) system. Because Osirix performs search based on the semantics of the documents, it can find more relevant documents than classic search engines can. XML & knowledge management HTML would seem the natural choice for Web documents because it is the most popular language for them. However, because of HTML's drawbacks (see the sidebar "From HTML to XML"), we prefer XML for a document-and Web-based corporate memory. XML, which derives from SGML, defines a standard for document formation. A DTD (document type definition) is a syntactic specification used as a model for XML documents. It contains definitions of the elements and their attached attributes. A document is considered valid if it conforms to its associated DTD. XML offers major advantages for corporate-memory management, combining the benefits of SGML and the Web: An information-exchange standard. To facilitate communication and exchange of information or knowledge, a community (that is, a department, an enterprise, a group of companies of the same domain, a company and its related providers and clients, and so on) can use a DTD to define a standard domain-oriented or application-oriented vocabulary. Community members can then express documents or data with the defined XML markups and exchange them using these markups. An enterprise can thus define one or several DTDs for the documents that will constitute its corporate memory.

In order to help the knowledge engineer and the expert during knowledge acquisition phase, the ACACIA Group is working on a knowledge acquisition methodology and tool (KATEMES) allowing knowledge acquisition from multiple experts, exploiting the specificities of design problems and preparing the assistance to the end-user and the quality of explanations he will be provided with. This paper describes our research program. After a brief description of our previous knowledge acquisition tool 3DKAT, we will present the primitives of KATEMES and the problems we intend to study and the ideas we intend to deepen about the link between knowledge acquisition and explanations, knowledge acquisition from multiple experts and methodological aspects.