A Quick Introduction to Metadata Michael Day UKOLN: The UK Office for Library and Information...
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Transcript of A Quick Introduction to Metadata Michael Day UKOLN: The UK Office for Library and Information...
A Quick Introduction to Metadata
Michael Day
UKOLN: The UK Office for Library and Information Networking, University of Bath
http://www.ukoln.ac.uk/
Running a Public Library WebsiteA workshop organised by UKOLN in association with EARL
University of Bath, 15-16 November 1999
Running a Public Library Website, University of Bath, 15-16 November 1999
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Presentation Outline
• Some definitions• Metadata and the Web
– RDF
• Resource discovery– Dublin Core– Information Gateways
• Other metadata implementations– Digital preservation
Running a Public Library Website, University of Bath, 15-16 November 1999
3
Metadata: definitions (1)
Metadata = data about data
“… the Internet-age term for structured data about data” - Joint NSF-EU Working Group on Metadata (1998)
“… structured data about data that imposes order on a disordered information universe” - Carl Lagoze (Cornell University)
Running a Public Library Website, University of Bath, 15-16 November 1999
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Metadata: definitions (2)
“… machine understandable information about web resources or other things” - Tim Berners-Lee (World Wide Web Consortium)
Roles:• Provides information about resources• Supports operations carried out on
information objects
Running a Public Library Website, University of Bath, 15-16 November 1999
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Metadata: uses
Metadata can support many potential applications:
• Resource discovery• Content ratings• E-commerce• Authentication• Data management• Intellectual property rights management• Digital preservation
Running a Public Library Website, University of Bath, 15-16 November 1999
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Metadata and the WebMetadata - the missing architectural component from the initial implementation of the Web
Metadata - RDF
PICS, TCN,
MCF, DSig,
DC,...
AddressingURL
Data formatHTML
TransportHTTP
Running a Public Library Website, University of Bath, 15-16 November 1999
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RDF
The Resource Description Framework:• Part of the W3C (World Wide Web
Consortium) Metadata Activity• Developing a common syntax for
expressing assertions about information on the web
– RDF Syntax Working Group– RDF data model and RDF/XML syntax– RDF Schema Working Group
http://www.w3.org/Metadata/
Running a Public Library Website, University of Bath, 15-16 November 1999
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Resource discovery
Main approaches:– Robot-based Web index services
(AltaVista, Lycos, etc.) – Utilising human intelligence to identify and
evaluate Internet resources.– Links pages– Information gateways
– The library cataloguing method, creating bibliographic records for Internet resources in library catalogues (InterCat)
Running a Public Library Website, University of Bath, 15-16 November 1999
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A metadata typology
Simple Rich
Adapted from: L. Dempsey and R. Heery, “Metadata: a current view of practice and
issues”, Journal of Documentation, vol. 54, no.2, March 1998, pp. 145-172.
Band One Band Two Band Three
(full textindexes)
(simplestructuredgenericformats)
(more complexstructure,domainspecific)
(part of largersemanticframework)
Proprietaryformats
ProprietaryformatsDublin CoreROADSIAFA/Whois++templates
FGDCMARC
TEI headersICPSREADCIMI
Running a Public Library Website, University of Bath, 15-16 November 1999
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The Dublin Core
Dublin Core Metadata Initiative (DCMI):• An initiative to define a core set of
metadata elements for resource discovery on the Internet
• 7 DC workshops– “ ... the broadest international, interdisciplinary
effort in resource description on the Internet ... the leading initiative for improving resource discovery on the Web” - Stu Weibel (OCLC)
http://purl.oclc.org/dc
Running a Public Library Website, University of Bath, 15-16 November 1999
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DC elements15 Elements:
• Title
• Subject
• Description
• Creator
• Publisher
• Contributor
• Date • Type
Semantics defined in Internet RFC 2413 (1998); now superseded by DC version 1.1
• Format • Identifier • Source • Language • Relation• Coverage • Rights
Running a Public Library Website, University of Bath, 15-16 November 1999
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DC qualifiers
DC-4 Workshop (Canberra):
• TYPE, SCHEME and LANGUAGE
DC Data Model working group:
• Element Qualifiers - refine the semantics of a DC element
• Value Qualifiers - gives context to the element value by
– indicating how to parse the value, e.g. an ISO 8601 date
– indicating the use of controlled vocabularies, e.g. LCSH, DDC or LCNAF
• Value Components
Running a Public Library Website, University of Bath, 15-16 November 1999
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DC syntax
Guidelines and tools developed:• “Encoding DC Metadata in HTML”
(Internet-Draft)• Data Model working group - “Guidance
on expressing DC within the RDF” (working draft)
• Creation tools - e.g., DC-dot:
Some examples ...
http://www.ukoln.ac.uk/metadata/dcdot/
Running a Public Library Website, University of Bath, 15-16 November 1999
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DC in HTML (1)<html>
<head>
<title>Dorset Library Service</title>
<link rel="schema.DC" href="http://purl.org/dc">
<meta name="DC.Title" content="Dorset Library Service">
<meta name="DC.Subject" content=”public libraries; Dorset County Council">
<meta name="DC.Publisher" content="European Regional Internet Registry/RIPE NCC">
<meta name="DC.Date" scheme="WTN8601" content="1999-08-05">
<meta name="DC.Type" content="Text">
<meta name="DC.Format" content="text/html">
<meta name="DC.Format" content="3791 bytes">
<meta name="DC.Identifier" content="http://www.dorset-cc.gov.uk/library.htm">
</head>
Running a Public Library Website, University of Bath, 15-16 November 1999
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DC in HTML (2)<html>
<head>
<title> Bath and North East Somerset Library and Archives</title>
<link rel="schema.DC" href="http://purl.org/dc">
<meta name="DC.Title" content="Bath and North East Somerset Library, and Archives">
<meta name="DC.Subject" content=”public libraries; archives; Bath and North East Somerset">
<meta name="DC.Publisher" content="Bath University">
<meta name="DC.Date" scheme="WTN8601" content="1999-06-23">
<meta name="DC.Type" content="Text">
<meta name="DC.Format" content="text/html">
<meta name="DC.Format" content="2719 bytes">
<meta name="DC.Identifier" content="http://hosted.ukoln.ac.uk/libweb/bathnes/">
</head>
Running a Public Library Website, University of Bath, 15-16 November 1999
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DC in RDF/XML<?xml version="1.0"?><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.0/"> <rdf:Description about="http://www.earl.org.uk/index.html”> <dc:title> EARL, the Consortium for Public Library Networking </dc:title> <dc:creator> EARL Consortium </dc:creator> <dc:type>Text</dc:type> <dc:format>4699 bytes</dc:format> <dc:language> en </dc:language> </rdf:Description></rdf:RDF>
Running a Public Library Website, University of Bath, 15-16 November 1999
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In abbreviated syntax<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.0/"> <rdf:Description about="http://www.earl.org.uk/index.html" dc:Title="EARL, the Consortium for Public Library Networking" dc:Creator="EARL Consortium [email protected]" dc:Subject="earl, public libraries, uk, networking, consortium" dc:Publisher="EARL Consortium [email protected]" dc:Date="1999-10-20" dc:Type="Text" > <dc:format> <rdf:Bag rdf:_1="text/html" rdf:_2="4699 bytes" /> </dc:format> </rdf:Description> </rdf:RDF>
Running a Public Library Website, University of Bath, 15-16 November 1999
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DC Implementations
• DC creation tools– DC-dot– Nordic Metadata Project - Template
• Metadata-aware indexing tools– DESIRE - Combine
• Conversion tools– Metadata Cross-walks– Nordic Metadata Project - d2m– Project BIBLINK
• Interoperability– AHDS Gateway
Running a Public Library Website, University of Bath, 15-16 November 1999
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Information Gateways
Roles of gateways:• Selection
– Gateways select resources according to some pre-defined criteria (e.g. subject area, some measure of quality)
• Creation of metadata– Gateways create simple resource
descriptions that can be both searched and browsed
Running a Public Library Website, University of Bath, 15-16 November 1999
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The eLib programme
JISC funded:• Selected gateways (SOSIG, EEVL, OMNI,
Biz/ed, History, etc.)• ROADS Resource Organisation and
Discovery in Subject-based services– Developing Web-based tools for information
gateways
– Cross-searching (Whois++)
– Content creation rules (cataloguing guidelines)
http://www.ilrt.bris.ac.uk/roads/
Running a Public Library Website, University of Bath, 15-16 November 1999
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The RDN
Resource Discovery Network• Funded by JISC, ESRC and AHRB• Co-operative network:
– Independent service providers (hubs) – Resource Discovery Network Centre
(RDNC)– Set service standards– Collection management policy– Develop strategic partnerships
– Cross-searching across multiple hubs
Running a Public Library Website, University of Bath, 15-16 November 1999
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Digital preservation
A variety of preservation strategies are available - all are dependent upon the creation, capture and storage of metadata
• Recent initiatives include:– Reference Model for an Open Archival Information
System (OAIS) – Research Libraries Group (RLG) Working Group
on Preservation Issues of Metadata– Cedars project - funded by JISC under eLib,
managed by Consortium of University Research Libraries (CURL)
– Digital Services Project - National Library of Australia
Running a Public Library Website, University of Bath, 15-16 November 1999
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UKOLN
UKOLN is funded by the Library and Information Commission, the Joint Information Systems Committee (JISC) of the higher education funding councils, as well as by project funding from the JISC and the European Union. UKOLN also receives support from the University of Bath, where it is based.
http://www.ukoln.ac.uk/