Application Profiles: interoperable friend or foe? Rachel Heery Michael Day TEL Milestone Conference Frankfurt am Main, 29-30 April 2002

Application Profiles: interoperable friend or foe?

Rachel HeeryMichael Day

TEL Milestone ConferenceFrankfurt am Main, 29-30 April 2002

TEL Milestone

Conference, Frankfurt am Main, 29-30 April 2002

Themes of the presentation

• Increase in schema creation activity• Tension between differentiation and

interoperability• Counterbalances to proliferation of

portals – sharing schema

– regard for end-user requirements

– controlled evolution of vocabularies

– cross standard interoperability

• Rôle of information professionals ...

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Definitions...

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Definition of Element Set

An element set is coherent bounded set of terms formulated as a basis for metadata creation

• Designed for particular purpose e.g. domain-specific, resource description, rights

• Identifies designated authority

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Definition of Schema

An schema is a structured representation that defines and identifies terms in an element set

• Provides authoritatve declaration of terms • Indicates semantic relationship of terms• Supports unique identification of terms• Typically schema will be expressed on

RDF or XML schema language

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Definition of Application Profile

An application profile is a schema which consists of terms (metadata elements) drawn from one or more element sets optimised for a particular local application

• Application profiles are declarations of usage

• Application profile reuse terms already defined elsewhere; or use terms from a local element set

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Schema

Declares set of terms with identifiers, definitions and comments

Self reliant

Means of declaring ‘new terms’

Application profile schema

Declares set of terms used in particular application or domain

Optimised for that application or domain

Re-uses terms from elsewhere

Means of declaring terms that an application uses and understands

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Increase in schema creation activity

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Optimisation and adaptation

MARC local fields• 9XX and XX9 tags

Z39.50 application profiles• sub-sets of standard appropriate for

application area

IMS• UK Further Education extension

Dublin Core domain specific elements and qualifiers

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New application profilesRSLP Collection Level description

DC Government

DC Libraries

DC Education

Australian Government Locator Service

Food and Agricultural Organisation

European Environment Agency

Renardus

EASEL,

Schoolnet

Various UK educational initiatives

etc., etc.

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Sharing schemas ...

• Standard solutions are publishedbut

• Implementers’ adaptations/extensions are not made widely available

Has this led to unnecessary proliferation of schemas, to duplication and repetition?

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Characterising requirements

Implementers need to declare various characteristics of their schema:

• terms used• whether a term is mandatory• any refined definitions of terms from existing

namespaces• which schemes must be used for content• other rules for content

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How to share ...

Best practice for sharing schema

"What terms does your metadata use?"

Need to express in “comparable“ way:– Which standard terms are used in an application– How terms are adapted or used locally– Other related usage notes

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Registries of schemas

To give access to schemas– searching and browsing – names, definitions, usage– relationships between terms

Support evolution of schemas– top-down (standards authorities)– bottom-up (real world usage)

Disclosure, discovery, effective reuse, harmonisation

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Publishing schemas and application profiles

Why?• To inform and promote• To provide authoritative version• To facilitate inter-working

To support• Evolution• Alignment

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Registries

MetaForm at the State and University Library in Göttingen

MEG registry serving UK Metadata for Education group

SCHEMAS registry EC funded, serving European projects (soon to be CORES!)

DCMI registry prototypes: access to information on DCMI terms

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Balancing standardisation and differentiation ...

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Increase in schema creation activity

Implementers must decide on appropriate metadata for a new service or system ... but what? Is there a single answer?

• Re-use• Interoperability• Users want coherent services

• But all want new, innovative services

Tension between alignment and differentiation

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Difficult issues!

People are keen to reach consensus, but….

Inconsistent approach in practice• When should implementers create new terms? • When should implementers try to add terms to

existing element sets?

Varying practice about creation of local element sets

Messy issue of data models

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Is a new DCMI term required?[Based on Stuart Sutton’s Action Chart!]

When faced with requirement for schema:– Use existing single schema where possible

– else

– Will use of domain specific scheme meet requirement?– else

– Will term from another schema meet requirement?– else

– Will a new domain-specific qualifier meet practice?– else

– Create local term?/Recommend schema extension?

Then declare terms ...

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Meeting user requirements..

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Quality control

How well does metadata meet needs of user?• Needs to be awareness of quality and

information retrieval issues in schema design

Some suggested criteria:• effectiveness of retrieval• effectiveness of display of retrieved record• cost of metadata creation• barriers to interoperability

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Evolution of element sets

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Managing evolution of element setsOrdered procedure for new terms

• approval process• historical record of changes

Top-down (committee structure) or bottom-up (feedback from usage statistics

Possibilities for automation?• Registration of new terms• harvesting existing metadata

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Cross standard interoperability

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Collaboration between standardisation bodies

• acknowledging overlapping semantics• honouring namespaces i.e. re-use

elements from existing element sets

• reach consensus on ‘core elements’• reach consensus on data models for

declaring schema• collaborate on registries

This is the agenda of CORES project!

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Information on standards

Practitioners need accessible information• Overviews of standards development• Reviews of schema-creating activities

Need information on inter-relation of standards in relation to schema e.g. Z39.50 attribute sets and DC schema

Need commentary and guidance information

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The rôle of the information professional?

• Tradition of collaboration within library world

• Ability to articulate needs of end-user communities

• Expertise in information retrieval techniques

• Ability to create user-friendly, accessible documentation

• Healthy scepticism of technology?

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Can contribute to

• Lobbying for infrastructure for sharing schema, moving from projects to services

• Lobbying for tools• Helping build tools• Involvement in standardisation process• Putting in quality control

• Considering costs, developing business models ...

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Further reading

Rachel Heery & Manjula Patel, “Application Profiles: mixing and matching

metadata schemas,” Ariadne, 25, September 2000: http://www.ariadne.ac.uk/issue25/app-profiles/

Thomas Baker, Makx Dekkers, Rachel Heery, Manjula Patel & Gauri Salokhe, “What terms does your metadata use? Application Profiles as machine-understandable narratives,” Journal of Digital Information, 2 (2), November 2001: http://jodi.ecs.soton.ac.uk/Articles/v02/i02/Baker/

Heike Neuroth & Traugott Koch, “Metadata mapping and application profiles: approaches to providing the cross-searching of heterogeneous resources in the EU project Renardus,” Proceedings of DC-2001: http://www.nii.ac.jp/dc2001/proceedings/

SCHEMAS Registry: http://www.schemas-forum.org/registry/

DCMI Registry: http://wip.dublincore.org:8080/registry/Registry

CORES: http://www.cores-eu.net

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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/

Documents

Application Profiles: interoperable friend or foe? Rachel Heery Michael Day TEL Milestone Conference Frankfurt am Main, 29-30 April 2002