Here's (a draft version of) a short document which suggests how the
Dublin Core elements might be represented using the WHOIS++ protocol
- see RFC 1835.
I'm thinking that this and a companion document detailing use with
X.500/LDAP might be successful in either the ASID or IDS working
groups of the IETF, which are both interested in directory service
schemas.
Comments welcome!
Martin
**DRAFT** Martin Hamilton
Loughborough University
Patrik Faltstrom
Tele2/Swipnet
Leslie L. Daigle
Bunyip Information Systems, Inc.
Jon Knight
Loughborough University
August 1996
Representing the Dublin Core within WHOIS++
Abstract
The Dublin Core is a simple resource description format which arose
out of a loose grouping of "librarians, archivists, humanities
scholars and geographers, as well as standards makers in the
Internet, Z39.50 and Standard Generalized Markup Language (SGML)
communities" [1].
It has recently been augmented by the Warwick Framework [2,3], which
provides a simple extension mechanism - allowing arbitrary additional
information to be packaged up with Dublin Core records without
changing the Dublin Core itself.
This document describes a mapping from the abstract model of the
Dublin Core a simple Internet search and retrieval protocol known as
WHOIS++ [4], and proposes a means of incorporating extensibility via
the Warwick Framework.
1. The Dublin Core in WHOIS++
The Dublin Core defines the following thirteen elements:
Element Description
------------------------------------------------------------------
Subject The topic addressed by the work
Title The name of the object
Author The person(s) primarily responsible for the
intellectual content of the object
Publisher The agent or agency responsible for making the
object available
Other-Agent The person(s), such as editors and transcribers, who
have made other significant intellectual
contributions to the work
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Date The date of publication
Object-Type The genre of the object, such as novel, poem, or
dictionary
Form The physical manifestation of the object, such as
Postscript file or Windows executable file
Identifier String or number used to uniquely identify the object
Relation Relationship to other objects
Source Objects, either print or electronic, from which this
object is derived, if applicable
Language Language of the intellectual content
Coverage The spatial locations and temporal durations
characteristic of the object
Each of these elements is optional, and each may be repeated.
We propose that these (with the above punctuation) be used as WHOIS++
attributes, and that the record type "DC-DOCUMENT" be used to
represent a WHOIS++ record which uses the Dublin Core element set.
For example, a "Title" element which had the value "Cities of The Red
Night" would be represented within WHOIS++ as the attribute/value
pair:
Title: Cities of The Red Night
One aspect of the Dublin Core does not translate directly to WHOIS++
- each element may have additional qualifying "scheme" information
attached to it. This provides the creator of the record with a means
of indicating additional semantics, e.g. the classification scheme
being used in the "Subject" element.
Since WHOIS++, like most Internet based search and retrieval
protocols, is attribute/value oriented, it is necessary to find a
place to put this extra information. We propose that it be placed in
an additional attribute/value pair which precedes the main
information about the element. For example, if the subject
classification for the above book were 813 in the Dewey Decimal
system, the resulting Dublin Core record expressed via WHOIS++ might
look like this:
Subject-Scheme: DDC
Subject: 813
Since the order of the attribute/value pairs in a WHOIS++ record is
significant, this provides a simple and easily implemented mechanism
for grouping together elements and their qualifying information.
Needless to say, scheme information should only appear in the WHOIS++
record if the attribute it qualifies also appears!
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**DRAFT** August 1996
It should be noted that the "Relation" element has an additional
qualifier, "type", which we propose be incorporated into WHOIS++
records by following the approach used with the "scheme" information.
2. The Warwick Framework in WHOIS++
The Warwick Framework provides a conceptual approach to extending the
abstract model of the Dublin Core to incoporate arbitrary additional
information. This means that the Dublin Core itself need not be
altered in order to meet the needs of particular user communities.
We propose that a WHOIS++ record type "DC-CONTAINER" be used to bind
together multiple packages of Dublin Core and other meta-information
which pertain to a given object. This is a subject for further
study.
3. Security considerations
Security considerations are not discussed in this document.
4. Conclusions
This document has shown how the abstract resource description
proposals of the Dublin Core and the Warwick Framework may be used
within the WHOIS++ protocol.
It should be apparent that a little care is necessary when delivering
this information via WHOIS++, but that this does not imply any great
implementation complexity.
5. Acknowledgements
Thanks to << ??? >> for their comments on draft versions of this
document.
This work was supported by grants from the UK Electronic Libraries
Programme (eLib), and the European Commission's Telematics for
Research Programme.
6. References
Request For Comments (RFC) and Internet Draft documents are available
from <URL:ftp://ftp.internic.net> and numerous mirror sites.
[1] S. Weibel. "Metadata: The Foundations of Resource
Description", D-Lib Magazine, July 1995.
<URL:http://www.ukoln.ac.uk/dlib/dlib/July95/07weibel.html>
<URL:http://www.dlib.org/dlib/July95/07weibel.html>
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**DRAFT** August 1996
[2] L. Dempsey, S. Weibel. "The Warwick Metadata Workshop:
A Framework for the Deployment of Resource Descrip-
tion", D-Lib Magazine, July/August 1996.
<URL:http://www.ukoln.ac.uk/dlib/dlib/july96/07weibel.html>
<URL:http://www.dlib.org/dlib/july96/07weibel.html>
[3] C. Lagoze, C. Lynch and R. Daniel. "The Warwick Frame-
work: A Container Architecture for Aggregating Sets of
Metadata", Technical Report TR96-1593, Cornell Univer-
sity Department of Computer Science. June 1996.
<URL:http://cs-
tr.cs.cornell.edu/Dienst/UI/2.0/Describe/ncs
trl.cornell%2fTR96-1593>
[4] P. Deutsch, R. Schoultz, P. Faltstrom and C. Weider.
"Architecture of the WHOIS++ service", RFC 1835. August
1995.
7. Authors' addresses
Martin Hamilton
Department of Computer Studies
Loughborough University of Technology
Leics. LE11 3TU, UK
Email: [log in to unmask]
Patrik Faltstrom
Tele2/Swipnet
Box 62
Borgarfjordsgatan 16
S-164 94 Kista
Sweden
Email: [log in to unmask]
Leslie L. Daigle
Bunyip Information Systems Inc.
310 Ste. Catherine St. West
Suite 300
Montreal, Quebec, Canada
H2X 2A1
Email: [log in to unmask]
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Jon Knight
Department of Computer Studies
Loughborough University of Technology
Leics. LE11 3TU, UK
Email: [log in to unmask]
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