As of December 1998 all of the eLib Web Pages contain embedded Dublin Core metadata. The metadata is stored in a ROADS database and is dynamically converted to an XML representation of RDF (Resource Description Framework) as the pages are requested.
It is expected that search engines will begin to support embedded XML/RDF as RDF emerges as a standard way of encoding metadata. Early adoption of RDF is a way of encouraging this process.
Since the metadata is embedded in the eLib web pages it can be seem by viewing the HTML source for a page. The metadata is in XML/RDF format for machine readability.
A human viewable rendering of the metadata on each page is available by clicking on the "DC Metadata" link in the page footer.
Dublin Core is short for the Dublin Metadata Core Element Set which is a core list of metadata elements agreed at the OCLC/NCSA Metadata Workshop in March 1995. Dublin Core provides a standard format for metadata and ensures interoperability for the eLib metadata. The eLib metadata uses the 15 Dublin Core attributes where appropriate.
The eLib metadata is encoded using an HTML-compliant XML representation of RDF as described in the W3C 'Resource Description Framework (RDF) Model and Syntax Specification' .
Sample RDF:
<rdf:RDF xmlns:rdf="http://www.w3.org/TR/WD-rdf-syntax#" xmlns:dc="http://purl.org/dc/elements/1.0/"> <rdf:Description about="http://www.ukoln.ac.uk/services/elib/" dc:Title="eLib: The Electronic Libraries Programme " dc:Creator="eLib web-support" dc:Subject="eLib; Electronic Libraries Programme; JISC; digital libraries; eLib; elib; electronic; library; cultural; change; academia; libraries; librarians; academics; training; networks; awareness; metadata; document; delivery; digitisation; electronic; journal; on; demand; publishing; access; to; network; resources; subject; gateway; JISC; Joint; Information; Systems; Committee; electronic; document; delivery; electronic; short; loan; images; pre- prints; supporting; studies; quality; assurance; Ariadne" dc:Description="In 1993, an investigation into how to deal with the pressures on library resources, caused by the rapid expansion of student numbers and the world-wide explosion in academic knowledge and information, ..." dc:Publisher="UKOLN, University of Bath" dc:Type="text" dc:Format="text/html - 12445 bytes" dc:Identifier="http://purl.eu.org/NET/ELIB/911840794-12501" dc:Language="en" /> </rdf:RDF> |
The embedded RDF has been verified using the SiRPAC parser.
The ROADS software provides a set of primarily Web-based tools for creating, maintaining and searching collections of descriptions of Internet resources. Descriptions are held in ROADS records, typically based on the DOCUMENT and SERVICE ROADS templates. The ROADS software is commonly used to build 'subject gateways'; searchable indexes of Internet resources in a particular subject area.
A new DUBLINCORESIMPLE ROADS template has been developed for storage of Dublin Core metadata in a ROADS database. This new template is used for the eLib metadata. Using ROADs to store metadata for the eLib web pages means that all metadata is centrally located and can easily be maintained.
Rather than inserting XML/RDF metadata into each eLib Web Page (which would be error prone and difficult to maintain) the metadata is embedded 'on the fly' using a server side include (SSI) directive. This SSI directive makes a call to a Perl script and inserts the output of that Perl script (the XML/RDF metadata) into the HEAD of the document.
The Perl script retrieves the appropriate metadata record from the ROADS database and converts it to XML/RDF. This approach allows other representations of the metadata to be generated such as META TAGS or the viewable HTML that can be accessed from the footer of each page.
The ROADS database containing eLib metadata was originally populated automatically using Perl scripts written for the task.
The metadata will be kept up-to-date by the eLib web support team using the ROADS template editor.
Maintainer: Tracy Gardner
Last Updated: 07 Jan 1999