An updated working draft is published.
This document is a revision of the RDF Schema working draft dated 9 April 1998. The major difference between this version and the previous version is that this version adopts a "property centric" approach whereas the previous version was "class-centric". In the previous version, Classes could be defined in a manner similar to an OO programming language like Java. A new class would have a number of "allowedPropertyType" arcs that pointed to property types which would be expected to occur on all instances of the class (modulo optionality constraints). For example, if we defined a class "Book", we might define it to have allowed property types of "author", "title", and "publisher". If all three of those were not defined, then we did not have a legal occurance of a "Book" node. This approach is familiar to many, because of its similarity to programming. It works well if things can be designed in advance. However, our direction is to allow a very free-flowing annotation style, and we believe that may not fit in with heavily pre-designed class hierarchies.
This version of the specification adopts a property-centric approach. Instead of defining a Class in terms of the Properties it has, we define Properties in terms of the Classes they may connect. That is the role of the RDFS:domain and RDFS:range constraints. For example, we could define the "author" property to have a domain of "Book" and a range of "String". The benefits of the property centric approach are that it is very easy for anyone to say anything they want about existing resources, which is one of the axioms of the web. Feedback on this point is particuarly encouraged.
This draft specification is a work in progress representing the current consensus of the W3C RDF Schema Working Group. This is a W3C Working Draft for review by W3C members and other interested parties. Publication as a working draft does not imply endorsement by the W3C membership. We caution that further changes are possible and therefore we recommend that only experimental software or software that can be easily field-upgraded be implemented to this specification at this time. The RDF Schema Working Group will not allow early implementation to constrain their ability to make changes to this specification prior to final release.
The Resource Description Framework is part of the W3C Metadata Activity. The goal of this activity, and of RDF specifically, is to produce a language for the exchange of machine-understandable descriptions of resources on the Web. A separate specification describes the data model and syntax for the interchange of metadata using RDF.
This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to use W3C Working Drafts as reference material or to cite them as other than "work in progress".
Note: As working drafts are subject to frequent change, you are advised to reference the above URL for "Latest version" rather than the URLs for working draft versions themselves. The latest version URL will always point to the most current version of this draft.
Note: The HTML source of this document contains embedded RDF and will therefore not validate by the HTML4.0 DTD. A solution for those requiring DTD-style validation services may come from future W3C work.
Comments may be sent to www-rdf-comments@w3.org. The public archive of these comments is available at http://lists.w3.org/Archives/Public/www-rdf-comments/
Revision 1.2 1998/08/14 16:54:08 swick Fix style. Revision 1.1 1998/08/14 16:11:05 swick created