Rick Silterra will be speaking on the Resource Description Framework (RDF). His talk will serve as an introduction to RDF and will discuss:
Silterra is a programmer in CTS and DLIT. He has a Bachelors in Linguistics from Cornell and a MLS from Syracuse. He has worked in the telecommunications industry specifying and programming interactive voice response systems, and served on the W3C committee specifying the VoiceXML language. Recently employed in the library industry, he has worked on creating DTD's and XSL transformations for the ENCompass system. His interest in hypertext systems was first sparked by XANADU.
At the April meeting of the Metadata Working Group, Rick Silterra from CUL spoke on RDF. Before he was introduced, the Group was reminded about May's Metadata Working Group on metadata quality-control issues, presented by Tom Bruce, Director of the Legal Information Institute at Cornell's Law School. In addition, the Group was asked to take a look at and provide feedback about the new Working Group home page, located at <http://metadata-wg.mannlib.cornell.edu/>.
Rick Silterra of CTS' Metadata Services group and DLIT's Library Systems group talked about a number of features associated with the Resource Description Framework, or RDF. After introducing RDF, he discussed the relationship and syntax of RDF and XML, projects currently using RDF, how RDF can be used to enhance interoperability, some RDF query languages currently in use, and how RDF queries can bring together information from various sources.
RDF is a tool of the semantic web. It was first recommended as a model and syntax in 1999, and the RDF Schema Specification was introduced in 2000. The most recent specification was introduced in February, 2004.
RDF has a number of goals: to provide information about Web resources and the systems that use them; to allow data to be processed outside the particular environment in which it was created; to step up categorization and classification from simple term searching to concept searching; and to describe capabilities like CC/PP. These goals--to share data between applications across the web and to reuse data between different applications--seem quite similar to those of XML. However, XML is a data format standard, and the tree-like structure of an XML document can get in the way of analyzing the information; one must understand the structure of an XML document in order to properly query it.
Some of the key concepts of RDF include: it is an expression of simple facts; it is a graph data model (not a tree); it functions with a URI-based vocabulary; different syntaxes can be used to represent the assertions including RDF/XML; and there does not have to be a strict hierarchy because "groves" of data are possible.
RDF assertions are formed with subject/predicate/object triples and can be serialized in a number of different ways, including N3 statements and XML. RDF uses a number of different types of containers, including "bag", "seq", and "alt".
Silterra also covered Rich Site Summary, or RSS, and briefly discussed RDF query languages. RSS is an application of RDF used to "syndicate" information about web sites. RDF database query languages allow the user to merge information from different ref sources. Such query languages include Inkling and Squish, as well as RDQL.
