The relation between ontologies and schema-languages

Semantic Web Information Management, 2009

The Semantic Web is basically an extension of the Web and of the Web-enabling database and Internet technology, and, as a consequence, the Semantic Web methodologies, representation mechanisms and logics strongly rely on those developed in databases. This is the motivation for many attempts to, more or less loosely, merge the two worlds like, for instance, the various proposals to use relational technology for storing web data or the use of ontologies for data integration. This article comes second in this book, after an article on data management, in order to first complete the picture with the description of the languages that can be used to represent information on the Semantic Web, and then highlight a few fundamental differences which make the database and Semantic Web paradigms complementary but somehow difficult to integrate.

2010

So far we have considered expressing information within the XML language. XML is not a very expressive language: it basically provides a structure which stores information and this information has to be extracted in order to be accessed and exploited. It does not allows to express knowledge in terms of descriptions which will be used for guiding this interpretation.

Computer Networks, 2002

Recently, there has been a wide interest in using ontologies on the Web. As a basis for this, RDF Schema (RDFS) provides means to define vocabulary, structure and constraints for expressing metadata about Web resources. However, formal semantics are not provided, and the expressivity of it is not enough for full-fledged ontological modeling and reasoning. In this paper, we will show how RDFS can be extended in such a way that a full knowledge representation (KR) language can be expressed in it, thus enriching it with the required additional expressivity and the semantics of this language. We do this by describing the ontology language OIL as an extension of RDFS. An important advantage of our approach is a maximal backward compatability with RDFS: any meta-data in OIL format can still be partially interpreted by any RDFS-only-processor. The OIL extension of RDFS has been carefully engineered so that such a partial interpretation of OIL meta-data is still correct under the intended semantics of RDFS: simply ignoring the OIL specific portions of an OIL document yields a correct RDF(S) document whose intended RDFS semantics is precisely a subset of the semantics of the full OIL statements. In this way, our approach ensures maximal sharing of meta-data on the Web: even partial interpretation of meta-data by less semantically aware processors will yield a correct partial interpretation of the metadata. We conclude that our method of extending is equally applicable to other KR formalisms.

Lecture Notes in Computer Science, 2000

The popularity and press surrounding the release of XML has created widespread interest in standards within particular communities that focus on representing content. The dream is that these standards will enable consumers and B2B systems to more accurately search information on the Web within these communities. We believe the expansiveness and diversity of the Web creates a need for a small set of standard semantic primitives that have the same meaning and interpretation across communities. Such a standard set of primitives should take into account existing efforts in ontology, and in e-commerce content standards. We are investigating existing content standards proposals for the Web, and present here a large, but by no means complete, list of these standards efforts classified by their ontological sophistication and their intent. We then propose some very preliminary notions of how these standards could be harmonized to produce a set of standard semantic primitives for describing content.

AAAI Workshop, Edmonton AB, 2002

The goal of semantic web research is to allow the vast range of web-accessible information and services to be more effectively exploited by both humans and automated tools. To facilitate this process, RDF and OWL have been developed as standard formats for the sharing and integration of data and knowledge-the latter in the form of rich conceptual schemas called ontologies. These languages, and the tools developed to support them, have rapidly become de facto standards for ontology development and deployment; they are increasingly used, not only in research labs, but in large scale IT projects. Although many research and development challenges still remain, these "semantic web technologies" are already starting to exert a major influence on the development of information technology.