Knowledge Organisation Systems
Doug Tudhope
Hypermedia Research Unit
University of Glamorgan
Schemas and Ontologies Workshop, NeSC, May 2003
Presentation
• Introduce Knowledge Organisation Systems (KOS)
• Review some current DL work on KOS
• Research Issues
– draw connections with Ontologies and Semantic Grid
• General sources
– NKOS: Networked Knowledge Organization
Systems/Services
• http://nkos.slis.kent.edu/
– SEMKOS FP6 IP Proposal
• http://www.lub.lu.se/SEMKOS/
Taxonomy of Knowledge Organisation Systems
• Term Lists
– Authority Files, Glossaries, Gazetteers, Dictionaries
• Classification and Categorization
– Subject Headings
– Classification Schemes and Taxonomies
• eg DDC, scientific taxonomies
• Relationship Schemes
– Thesauri
– Semantic Networks
– (Ontologies)
Hodg00, http://www.clir.org/pubs/abstract/pub91abst.html
KOS ctd.
• Thesauri
– 3 Standard Relationships between concepts
• Equivalence, Hierarchical, Associative
– Domain (lead-in) vocabulary
– Concept definitions and warrant (Scope Notes)
• Ontologies
– Higher level conceptualisation
• formal definition of relationships
• inference rules and definition of roles
• KOS an element of ontologies and schemas
Jaco03, Ontologies and the Semantic Web,.
ASIST Bulletin, April/May 2003, Special Issue on Semantic Web
KOS Legacy
• Large (multilingual) vocabularies, indexed multimedia
(and print) collections, scientific taxonomy initiatives
• Product of peer review and follow standards
• Network of practice, training and mechanisms for
evolution
However
• Cannot currently be utilised to full potential
– Designed for human inspection, semantic structure not
explicitly represented
– May be inconsistently evolved from various sources
• Opportunity to formalise / enrich
– exploiting semantic web technologies
International Thesaurus Standards
• Ongoing initiatives to revise thesaurus standards
• ANSI/NISO Z39.19 (monolingual)
• IFLA (multilingual)
• BS 5723 and BS 6723 (both) - BSI public draft soon
Extended scope, comparisons, interoperability
• Various proposals to extend current relationships by
specialisation, enriching standards but maintaining
compatibility (eg Tudh01)
Representation of KOS in RDF/XML
• Various RDF/XML KOS-based projects
Eg
• Voc-ML XML Schema
http://nkos.slis.kent.edu/VOCML-1.DOC
http://www.lub.lu.se/netlab/conf/busch.ppt
• RDF Thesaurus Interchange Format
Limber Project - ELSST multilingual thesaurus
http://www.ercim.org/publication/Ercim_News/enw51/wilson.htm
l
• DESIRE II - RDF Thesaurus Specification
http://ilrt.org/discovery/2001/01/rdf-thes/
NKOS Registry - draft proposal for KOS-level metadata
http://staff.oclc.org/~vizine/NKOS/Thesaurus_Registry_version3_rev.htm
Follows Dublin Core, data elements include:
KOS - Title, Creator, Publisher, Date, Type, Format,
Identifier, Language
KOS - Subject, Description, Application, Rights
Need for for more definition of purpose and usage?
- the ‘point of view’
KOS - Relation (URI etc)
KOS - Entity Types, Info Given, Relationships
Relationships defined via a standard Namespace?
Uniquely identify both the KOS and relationships
within the KOS.
Cross - mapping/browsing/searching KOS
•
Cross Mapping and semi-automatic KOS correlation
http://jodi.ecs.soton.ac.uk/Articles/v01/i08/Doerr/
– Related KOS versioning and update tools
eg obsoletion, sibling addition, change of meaning
– CIDOC Conceptual Reference Model
Cultural heritage metadata framework (ISO/CD 21127)
http://www.cultivate-int.org/issue9/chios/
• Renardus - common classification/browsing structure
and cross-browsing service
http://www.renardus.org
Research issues
• KOS services for DL and Semantic Grid
• Facet analysis and foundational concepts complementary approaches?
• Whole lifecycle considerations
KOS integration into DL services
Linda Hill Research Agenda for ASIST SigCR Workshop
http://www.lub.lu.se/SEMKOS/docs/Hill_KOSpaper7-2-final.doc
• General KOS service protocol from which protocols
for specific types of KOS can be derived
• Robust linking model in which DL entities (collections,
objects, and services) can refer to KOS entities
(concepts, labels, and relationships)
• Visualization tools that fully use and display the rich
semantics embedded in KOS
=> move towards a model of search service ‘flow’?
- how semantic search services combine
Standard protocols for distributed access
ADL Thesaurus Protocol (and Gazetteer Protocol)
– lightweight, stateless, based on XML, HTTP
Services include:
•
download -> list of all terms
•
query -> list of matching terms (equals/contains/fuzzy etc matches)
•
get-broader(starting-term, max-levels, format) -> hierarchy
– format: "term", "term-description", or "extended"
•
get-narrower([starting-term,] max-levels, format) -> hierarchy
• http://www.alexandria.ucsb.edu/thesaurus/protocol
see also
• Zthes Z39.50 protocol - http://zthes.z3950.org/index.html
Possible KOS-based Terminology Server
within JISC Information Environment
Content providers
Shared services
Provision
layer
Terminology
service
Authentication
Authorisation
Service
registry
4
5
Broker/Aggregator
Broker/Aggregator
3
2
Portal
Portal
Resolver
Inst’n Profile
Fusion
layer
1
End-user
Portal
Presentation
layer
Enriching / Formalising KOS
• Not only a matter of representation in RDF/XML
- may be inconsistencies in logical structure
eg combination of different hierarchical relationships
--> deconstruction and ontological formalisation
--> mutually exclusive concept structures
suitable for automatic methods
Facet analysis techniques relevant
• Faceted (analytico-synthetic) approaches
– based on fundamental, high-level categories
– synthetic rather than enumerative
• combine facets when indexing/querying
Facet Analysis
• UK Classification Research Group extended
Ranganathan's set of fundamental categories
• Entity, Part, Property, Material, Process, Operation,
Product, Agent, Space, Time, ...
• Mapped to facets for particular KOS
• Basis of several scientific and industrial KOS
• Useful for ‘cleaning’ KOS, multi-concept indexing
and potential for precision in search
However
• Synthesis rules for facet combination
lack formal expression
Foundational concepts and facets
 Foundational concepts and relations in ontologies
similar fundamental categories to CRG (and CRM)
but logically expressed and axiomatised
can provide
 Additional formalisms to logically express 'syntactical'
combination of facets (eg Bech01)
can assist
 Automatic generalisation (expansion)
of faceted multi-concept queries/descriptors
Faceted multi-concept generalisation (Tudh02)
http://www.glam.ac.uk/soc/research/hypermedia/facet_proj/
Need to consider whole lifecycle
• Importance of indexing for retrieval performance
• Inter-relation of different stages of lifecycle
(eg Bate02; Soer94)
• Make indexing practice more explicit?
– KOS Registry include description of indexing praxis?
• Differences in granularity, exhaustivity, specificity
in usage of different kinds of KOS
– eg Classification Vs Thesaurus (indexing language)
• Automatic KOS-based indexing/classification
– DESIRE II, Scorpion Projects
http://www.lub.lu.se/desire/DESIRE36a-overview.html
Need to consider whole lifecycle ctd.
• Cost/benefit issues when enriching KOS?
Different levels
specialisation of standard relationships first step?
Application dependent
• User interface critical
move beyond minimal assumptions
of current web search engines on
users, query structure, collections
NKOS Workshops at ECDL and JCDL
on related themes to this NeSC workshop
•
NKOS Workshop - Evolving Standards
ECDL2003, Trondheim, 21 August 2003
cfp soon - email dstudhope@glam.ac.uk
or see http://www.ecdl2003.org & http://nkos.slis.kent.edu
• NKOS Workshop - Building a Meaningful Web
JCDL03, Houston, Texas, May 31
see http://nkos.slis.kent.edu
• Selected papers from the NKOS workshops
will be considered for forthcoming special issues
of journals JoDI and NRHM
References
Bates, Marcia The Cascade of Interactions in the Digital Library Interface. Information Processing and
Management 38 (2002):381-400.
Bechofer S., Goble C. 2001. Thesaurus construction through knowledge representation. Data & Knowledge
Engineering, 37, 25-45.
CIDOC Conceptual Reference Model, http://www.cultivate-int.org/issue9/chios/
Cross P., Brickley D., Koch. T. 2000. Conceptual relationships for encoding thesauri …
http://www.desire.org/results/discovery/rdfthesschema.html
Doerr M. 2001. Semantic Problems of Thesaurus Mapping. Journal of Digital Information, 1(8) http://jodi.ecs.soton.ac.uk/Articles/v01/i08/Doerr/
FACET Project. http://www.glam.ac.uk/soc/research/hypermedia/facet_proj/
Global Taxonomy Initiative. http://www.biodiv.org/programmes/cross-cutting/taxonomy/gef-gti.asp
Hill et al. 2002. Integration of Knowledge Organization Systems into Digital Library Architectures. ASIST
SigCR - http://www.lub.lu.se/SEMKOS/docs/Hill_KOSpaper7-2-final.doc
Hodge Gail, 2000. Systems of Knowledge Organization for Digital Libraries: Beyond Traditional Authority
Files. CLIR Pub91. April 2000. http://www.clir.org/pubs/abstract/pub91abst.html
Jacob Elin. 2003. Ontologies and the Semantic Web. ASIST Bulletin, April/May 2003, Special Issue on
Semantic Web. http://www.asis.org/Bulletin/Apr-03/BulletinAprMay03.pdf
Janée G., Ikeda S., Hill L. 2002. ADL Thesaurus Protocol v1.0.
http://www.alexandria.ucsb.edu/thesaurus/protocol and http://nkos.slis.kent.edu/2002workshop/janee.ppt
Koch T., Ardoe A. 2000. DESIRE II Overview of Results and Demo.
http://www.lub.lu.se/desire/DESIRE36a-overview.html
References ctd.
Renardus Project - http://www.renardus.org
NKOS: Networked Knowledge Organization Systems/Services, http://nkos.slis.kent.edu/
NKOS Registry - draft proposal for KOS-level metadata
http://staff.oclc.org/~vizine/NKOS/Thesaurus_Registry_version3_rev.htm
SEMKOS FP6 IP Proposal, http://www.lub.lu.se/SEMKOS/
Soergel D. 1994 Indexing and retrieval performance: The logical evidence. Journal of American Society for
Information Science, 45(8): 589-599.
Taylor M. 2000. Zthes: a Z39.50 Profile for Thesaurus Navigation Version 0.4.
http://lcweb.loc.gov/z3950/agency/profiles/zthes-04.html
Tudhope D., Alani H., Jones C. 2001. Augmenting thesaurus relationships: possibilities for retrieval. Journal
of Digital Information, 1(8) - http://jodi.ecs.soton.ac.uk/Articles/v01/i08/Tudhope/
Tudhope D., Binding C., Blocks D., Cunliffe D. 2002. Compound Descriptors in Context: A Matching
Function for Classifications and Thesauri. Proc. 2nd Joint Conference on Digital Libraries. ACM Press. 8493 http://www.glam.ac.uk/soc/research/hypermedia/publications/jcdl02.pdf
VocML. 2000. Vocabulary ML Project. http://nkos.slis.kent.edu/VOCML-1.DOC and
http://www.lub.lu.se/netlab/conf/busch.ppt
Wilson M., Matthews B. 2002. Migrating Thesauri to the Semantic Web.
http://www.ercim.org/publication/Ercim_News/enw51/wilson.html
Contact Information
Doug Tudhope
School of Computing
University of Glamorgan
Pontypridd CF37 1DL
Wales, UK
dstudhope@glam.ac.uk
http://www.comp.glam.ac.uk/pages/staff/dstudhope