Metadata: an introduction

1
Metadata an introduction

• Michael Day
• UKOLN, University of Bath
• m.day_at_ukoln.ac.uk
• Managing Networks Understanding New
  Technologies, Birmingham, 13 September 2001

2
Presentation overview

• Defining metadata
• Dublin Core
• Background
• Exercise 1
• Semantics
• Syntax
• Content Rules
• Exercise 2

3
Metadata (1)

• Some definitions
• data about data
• Internet-age term for structured data about
  data - Joint NSF-EU Working Group on Metadata
  (1998)
• ... Machine understandable information about web
  resources or other things - Berners-Lee (W3C)
• Functional definition
• structured data about resources that can be used
  to help support a wide range of operations

4
Metadata (2)

• These operations may include
• resource discovery and access
• rights management
• e-commerce
• authentication
• collection management
• preservation

5
Metadata (3)

• Resource discovery metadata
• Provides support for
• searching
• location
• retrieval (delivery)
• description
• May help enable
• Semantic interoperability

6
Metadata (4)

• Where is metadata stored?
• Different models of metadata-resource
  association
• embedded within resource
• tightly coupled using protocols or identifiers
• separate database(s)

7
Metadata formats (1)

• Diversity of metadata formats and frameworks
• How many have you heard of?

8
Metadata formats (1)

• Diversity of metadata formats and frameworks,
  e.g.
• Dublin Core
• EAD, CIMI, TEI
• PICS, RDF
• MARC
• GILS, FGDC
• ROADS
• http//www.ukoln.ac.uk/metadata/glossary/

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Metadata formats (2)

• SCHEMAS Forum project Metadata Watch has
  already identified
• Over 200 implementation activities
• Around 90 standardisation activities
• Very different levels of information about the
  various initiatives

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Metadata formats (3)

• USMARC
• 245 00 Wordnews online h computer file.
• 246 3 World news online
• 256 Computer online service.
• 260 Washington, D.C. b Worldnews Online, c
  1995-
• 538 Mode of access Internet.
• 500 Title from title frame.
• 520 WorldNews OnLine is a service ...
• 650 0 Newspapers x Databases.
• 856 7 u http//worldnews.net 2 http

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Metadata formats (4)

• TEI header
• ltteiHeader type"aacr2"gtltfileDescgtlttitleStmtgt
• lttitle type"245"gtRubaiyat of Omar Khayyam the
  astronomer poet of Persia / rendered into English
  verse by Edward Fitzgerald with drawings by
  Florence Lundborglt/titlegt
• lttitle type"gmd"gtelectronic resourcelt/titlegt
• ltauthorgtOmar Khayyamlt/authorgt
• ltrespStmtgt
• ltrespgtConversion to TEI.2-conformant
  markuplt/respgt
• ltnamegtUniversity of Virginia Library Electronic
  Text Center lt/namegt
• lt/respStmtgt

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Metadata formats (5)

• ROADS/IAFA template
• Template-Type SERVICE
• Handle 871473886-23884
• Title Wellcome Unit for the History of Medicine
• URI-v1 http//units.ox.ac.uk/cgi-bin/safeperl/wuh
  minfo/p?home.html
• Admin-Email-v1 wuhmo_at_wuhmo.ox.ac.uk
• Publisher-Name-v1 Wellcome Unit for the History
  of Medicine
• Publisher-Postal-v1 45-47 Banbury Road, Oxford,
  OX2 6PE
• Publisher-City-v1 Oxford

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A metadata typology

• Simple
  Rich
• Based on Dempsey and Heery (1998)

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Who creates metadata?

• Service providers
• search services
• third parties
• commercial publishers

• Resource creators
• authors
• webmasters
• institutions

• hand crafted
• robot/database generated

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Metadata creation tools

• DC-dot
• http//www.ukoln.ac.uk/metadata/dcdot/
• Nordic Metadata Project Metadata Template
• http//www.lub.lu.se/cgi-bin/nmdc.pl
• Reggie Metadata Editor
• http//metadata.net/dstc/

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Aspects of metadata

• Syntax
• related to the technical implementation - e.g.
  MARC, XML
• Semantics
• the basic meaning of elements
• Rules for content
• e.g., cataloguing rules

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The Dublin Core Metadata Element Set
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Dublin Core (1)

• What is it?
• 15 element metadata set
• based on international consensus
• Some initial assumptions
• simple set for untrained creators
• basic set for semantic interoperability or
  resource discovery
• primarily for Web-based document-like objects
• http//www.dublincore.org/

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Dublin Core (2)

• Dublin Core Metadata Initiative
• Workshop series
• first workshop hosted by OCLC in Dublin, Ohio
  (1995)
• 9th workshop (DC2001) will be held in October
  (Tokyo)
• Working Groups
• for DC issues (e.g. Architecture, Registry,
  Standards, tools, etc.)
• for specific user communities (e.g. Libraries,
  Education, Government, etc.)
• open e-mail discussion lists

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Dublin Core (3)

• Dublin Core Metadata Element Set
• Version 1.0 (RFC 2413, 1998)
• Version 1.1 (1999)
• approved (Z39.85) by the US National Information
  Standards Organization (NISO) as a Draft American
  National Standard (July 2001)
• Dublin Core Qualifiers
• DCMI Recommendation (2000)

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DC exercise 1

• The Dublin Core Metadata Element Set consists of
  15 elements, designed for simple resource
  discovery.
• What elements do you think should be part of such
  a metadata element set?
• Think about the type of resources that need to be
  described
• Web pages
• Document-like objects
• Images, sound resources, etc.
• Multimedia resources

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Dublin Core semantics
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DC semantics (1)
15 element core metadata set

• Title
• Subject
• Description
• Creator
• Publisher
• Contributor
• Date
• Type

• Format
• Identifier
• Source
• Language
• Relation
• Coverage
• Rights

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DC semantics (2)

• An example
• Name Description
• Identifier Description
• Definition An account of the content of the
  resource.
• Comment Description may include but is not
  limited to an abstract, table of contents,
  reference to a graphical representation of
  content or a free-text account of the content.

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DC semantics (3)

• Qualifiers
• DC semantics are defined very broadly
• Possible to add qualifiers to some elements
• Element refinement(s)
• Relation.IsPartOf
• Date.Created
• Encoding scheme(s)
• Subject (schemeDDC)
• Date (schemeISO8601)

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DC syntax
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DC syntax (1)

• Can be embedded into HTML Web pages
• ltMETAgt tag
• limited functionality
• the data can be harvested by metadata-aware
  search engines (but not many do this)
• note that this is just one way of implementing
  the DC element set

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DC syntax (2)

• An example of embedding DC metadata in HTML 4.0
• lthtmlgtltheadgt
• lttitlegtUKOLN Home Pagelt/titlegt
• ltmeta name"DC.Title" content"UKOLN"gt
• ltmeta name"DC.Description" content"UKOLN is a
  national centre for support in network
  information management in the library and
  information communities. It provides awareness,
  research and information services"gt
• ltmeta name"DC.Creator" content"UKOLN
  Information Services Group"gt
• lt/headgt

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DC content rules
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DC content rules

• Not part of DCMI
• No content rules (cataloguing rules) defined as
  part of Dublin Core Metadata Element Set
• May be important where there are expectations of
  consistent cross-searching across related
  services, e.g.
• ROADS Cataloguing Guidelines
• Resource Discovery Network (RDN) Cataloguing
  Guidelines

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DC exercise 2

• Go to the Nordic Metadata Template at
• http//www.lub.lu.se/cgi-bin/nmdc.pl
• And try to create some metadata for a Web page
  that you know reasonably well
• Reflect on
• Which bits are difficult to fill in
• Which parts relate to semantics, which to content
  rules (e.g. inverted forms of names)

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Acknowledgements

• UKOLN is funded by Resource the Council for
  Museums, Archives and Libraries, the Joint
  Information Systems Committee (JISC) of the UK
  higher and further 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/