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 ...
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
Definitions...
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
Increase in schema creation activity
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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.
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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?
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
Publishing schemas and application profiles
Why?• To inform and promote• To provide authoritative version• To facilitate inter-working
To support• Evolution• Alignment
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
Balancing standardisation and differentiation ...
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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 ...
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
Meeting user requirements..
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
Evolution of element sets
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
Cross standard interoperability
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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!
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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?
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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 ...
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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
TEL Milestone
Conference, Frankfurt am Main, 29-30 April 2002
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/