Metadata

Storing Dublin Core Metadata in a ROADS database

 ROADS 

[This document is a part of DC-ROADS: ROADS as a (Dublin Core) Metadata Management Environment ]

Goal

The Dublin Core [1] provides a standard set of metadata elements for use in resource discovery. ROADS has been suggested as a tool for metadata management [2] with a ROADS database acting as the authoritative source of metadata for a website. It therefore makes sense to be able to extract Dublin Core metadata from a ROADS database. Alternatives for achieving this are discussed in this document.

This document only considers the representation of the basic 15 Dublin Core elements. Qualified Dublin Core is not considered at this point although this will become an issue in the near future.

UKOLN has a direct requirement to be able to extract Dublin Core metadata from a ROADS database and dynamically embed in into web pages. A Dublin Core template for this purpose is presented.

Options

ROADS does not currently support the direct storage of Dublin Core metadata, there are two main alternatives that could support the extraction of Dublin Core metadata from a ROADS database.

Map existing ROADS templates to Dublin Core

ROADS templates such as DOCUMENT and SERVICE contain similar information to the Dublin Core element set. One possibility would be to use existing ROADS templates to describe resources and then convert those templates to Dublin Core records when Dublin Core is required.

A mapping between the major ROADS templates and the Dublin Core elements sets already exists [3] so this option should be relatively straightforward.

This approach is the obvious solution if resources are already described according to a standard ROADS template.

Use a ROADS Dublin Core template

The main alternative to mapping existing ROADS templates to the Dublin Core is to create a ROADS template that represents Dublin Core so that no mapping is required.

This approach might be suitable in circumstances where the aim is to catalogue resources directly in terms of the Dublin Core, for example if the cataloguers are already familiar with the Dublin Core.

At its simplest a ROADS Dublin Core template would be:

# Dublin Core Basic
Template-Type:          DUBLINCOREBASIC
Handle::::m:
Title-v*::::o:
Creator-v*::::o:
Subject-v*::::o:
Description-v*::::o:
Publisher-v*::::o:
Contributors-v*::::o:
Date-v*::::o:
Type-v*::::o:
Format-v*::::o:
Identifier-v*::::o:
Source-v*::::o:
Language-v*::::o:
Relation-v*::::o:
Coverage-v*::::o:
Rights-v*::::o:

This template allows all 15 elements to be repeated with all elements being optional. The template type and handle attributes are added to provide a valid ROADS template.

The possibility of creating a new ROADS DOCUMENT template based on the Dublin Core is discussed in [4] . The main change from the above template is to suggest the use of ROADS 'clusters' for describing the complex elements Creator, Publisher, and Contributor. In [4] it is suggested that Creator and Contributor should be represented by a PERSON cluster and Publisher by an ORGANIZATION cluster. We modify this slightly to model all three complex elements using an AGENT cluster which has an attribute to distinguish between person and corporate body. This is a more flexible approach.

A simple AGENT cluster is defined as:

   
Template-Type:          AGENT
Handle::::o:
Name::::o:
Type:::Person|CorporateBody:o:
Email::::o:

This AGENT template is used within a slightly more complex template than the one above:

Template-Type:          DUBLINCORESIMPLE
Handle::::m:
Title::::o:
Creator-(AGENT*)::::o:
Subject::::o:
Description::::o:
Publisher-(AGENT*)::::o:
Contributor-(AGENT*)::::o:
Date-v*::::o:
Type::::o:
Format::::o:
Identifier-v*::::o:
Source::::o:
Language::::o:
Relation-v*::::o:
Coverage::::o:
Rights::::o:

Note that some elements have been made non-repeatable based on local requirements. A more general template would allow all elements to be repeated.

It may also be appropriate to add a RECORD element as discussed in [3] for recording metadata regarding the record itself (metadata author, creation date, etc).

The next step would be to create a ROADS template for qualified Dublin Core and to create authority files for elements with controlled vocabularies.

References

[1] - Dublin Core Home Page - http://www.purl.org/dc/
[2] - ROADS for (Dublin Core) Metadata Management - http://www.ukoln.ac.uk/metadata/roads/metadata-mgmt/
[3] - Mapping from Dublin Core to IAFA - http://www.ukoln.ac.uk/metadata/interoperability/dc_iafa.html
[4] - WHOIS++ templates - http://www.roads.lut.ac.uk/id/draft-ietf-asid-whois-schema-03.txt

[Next: ROADS for Metadata Management ]

Web page authored and maintained by:
Page created on: 10-May-99
Page last revised on: Wednesday, 26-May-1999 08:07:30 UTC

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