Séance du Séminaire “Philosophie du Web” : François Rastier & Yorick Wilks (12-13 mai 2012)

Nous aurons le privilège d’accueillir François Rastier et Yorick Wilks pour confronter la vision du Web Sémantique/Web de données à des approches davantage inspirées par la linguistique (notamment la linguistique des corpus).

Sémantique et idéologie du Web sémantique
François Rastier

Les ontologies sont le produit d’une théorie de la connaissance et d’une métaphysique concrétisée par leur sémantique. Le Web sémantique leur a donné un domaine d’application majeur. En passant du web des documents au web des données, il a affirmé la prééminence des métadonnées sur les données.

Les extensions au web des objets en témoignent et l’on doit souligner leurs implications économiques et militaires. De même pour le web des individus : la dualité entre ontologies et réseaux sociaux, web sémantique et socio-sémantique semble devenir une complémentarité. Les conséquences politiques et éthiques doivent évidemment être débattues.

The Semantic Web: meaning and annotation
Yorick Wilks
Florida Institute of Human and Machine Cognition.

The lecture discusses what kind of entity the Semantic Web (SW) is, in terms of the relationship of natural language structure to knowledge representation (KR). It argues that there are three distinct views on the issue: first, that the SW is basically a renaming of the traditional AI knowledge representation task, with all the problems and challenges of that task. If that is the case, as many believe, then there is no particular reason to expect progress in this new form of presentation, as all the traditional problems of logic and representation reappear and it will be no more successful outside the narrow scientific domains where KR seems to work even though the formal ontology movement has brought some benefits. The paper contains some discussion of the relationship of current SW doctrine to representation issues covered by traditional AI, and also discusses issues of how far SW proposals are able to deal with difficult relationships in parts of concrete science.

Secondly, there is a view that the SW will be the WorldWideWeb with its constituent documents annotated so as to yield their content or meaning structure more directly. This view of the SW makes natural language processing central as the procedural bridge from texts to KR, usually via a form of automated Information Extraction. This view is discussed in some detail and it is argued that this is in fact the only way of justifying the structures used as KR for the SW. There is a third view, possibly Berners- Lee’s own, that the SW is about trusted databases as the foundation of a system of web processes and services, but it is argued that this ignores the whole history of the web as a textual system, and gives no better guarantee of agreed meanings for terms than the other two approaches. The lecture also touches on the basic issues of how the above viewpoints relate to the basic issue of how elements of the SW gain meaning, and the views of Halpin and others are discussed. There are also some reflections of the origins of the SW in Berners-Lee’s own thinking and whether the SW was what he intended all along when the WWW was first set up.