European Conference on Digital Libraries
 Lisbon, Portugal, September 2000


Special Workshop on

Networked Knowledge Organization Systems (NKOS):

European initiatives and projects / options for global co-operation


Martin Doerr, Institute of Computer Science, Foundation for Research and Technology, Hellas (FORTH), Greece. Email:

Traugott Koch, NetLab, Lund University Library Development Department, Sweden. Email:

Douglas Tudhope, School of Computing, University of Glamorgan, Wales, UK. Email:

Repke de Vries, Netherlands Institute for Scientific Information Services, Netherlands. Email:


This half-day workshop aims to provide an overview of research, development and projects related to the usage of knowledge organization systems in Internet based services and digital libraries. These systems can comprise thesauri and other controlled lists of keywords, ontologies, classification systems, taxonomies, clustering approaches, dictionaries, lexical databases, concept maps/spaces, semantic road maps etc.

A second objective of the workshop is to enable and support co-operation between European initiatives in the area of networked knowledge organization and to provide a basis for participation in global efforts (see below for other NKOS projects) and standardization processes.

This workshop will be a chance to reach out to a broader group of people working in the area, to inform each other on on-going research and projects and to start discussions about possible common goals and tasks, including organizational efforts: e.g. setting up a regular event and communication or collaboration with global NKOS activities.

Workshop content and structure

The half-day workshop spans two conference sessions on September 20. The workshop will start with an introduction and short statements of experience and interests from all participants. The main content of the first session will be presentations from 4 invited panel speakers:

OIL: The Ontology Inference Layer
Sean Bechhofer, Computer Science Department, University of Manchester, UK

Thesaurus Mapping (abstract)
Martin Doerr,  Foundation for Research and Technology, Hellas (FORTH), Greece.

Report on NKOS activities in North America
Linda Hill, Alexandria Digital Library Project, University of California at Santa Barbara.

Having the Right Connections: The Limber Project
Ken Miller, Data Archive, University of Essex, UK

After lunch, the second workshop session will offer an opportunity for all participants to informally contribute position statements, research topics, project experiences and perspectives, leading into general (or optionally small-group) discussion. The workshop will conclude by considering options for cooperation and future activities.

To facilitate participation in the workshop, we encourage all interested participants to email short position statements to any of the workshop organisers. We have received the following statements:

Paul Doorenbosch, NIWI

NIWI (Netherlands Institute for Scientific Information Services does research about how a thesaurus could be of any help in formulating questions searching a (bibliographic) database. Previously thesauri were used in the first place in indexing: assigning keywords to (scientific) publications. Now a days we see thesauri used in electronic retrieval systems, but in the background. The NIWI website explicitely offers an online thesaurus to the enduser and gives him an opportunity to either use this tool or ignore it. By analysing standard and custom logging, NIWI tries to find out if and how endusers use this thesaurus and why they find or don't find an answer to their questions asked. The database used is in the field of Dutch social sciences.


In recent years, the need for knowledge organization in Internet services supporting resource discovery in digital libraries and related areas has been increasingly recognised. The growth of information on the Web continues to challenge Internet searchers to locate relevant, high quality resources. The major Web search services respond to this challenge by increasing the size of their databases and offering more powerful searching and ranking features.  In contrast to these global search engines, many smaller, more discriminating services are trying to improve resource discovery on the Internet by focusing their efforts on the selection, description, and subject arrangement of high-quality resources.

Most quality-based services go beyond selection and also catalog or describe chosen resources according to metadata standards such as the Dublin Core (DC). Quality-based services also commonly provide subject access to selected resources through formal knowledge organization structures such as a subject thesaurus, classification scheme, or both. Beyond the insufficiencies of existing individual services, especially the big search services, the overall resource discovery infrastructure on the Internet is not very well developed. For example, few support tools exist for assisting users in finding the right service to start with.  Connections among subject collections are also lacking. A user who discovers one service, e.g., about mechanical engineering, is not normally forwarded to related topics in another service. There is no discovery architecture or linkage among services based on subject indexing languages or domain ontologies.

Progress in the distributed usage of networked knowledge organization systems may well provide the key to good solutions for these resource discovery problems and be instrumental in dealing with the complexity of subject access to distributed digital information.

The issue poses questions of pure research, but also to a very high degree applied questions of agreement, collaboration, standardization, use and user needs. Problems of pure research concentrate around ontological questions of structuring and connecting large, multipurpose knowledge bases and on questions of advanced representation and reasoning mechanisms. The applied problems are characterized by the lack of data exchange format standards, communication protocols and reference architectures, in general a result of insufficient awareness of the relevance of global formal knowledge resources to access distributed, diverse and heterogeneous sources.

Workshop Topics

Digital library requirements for knowledge organization schemas:

Digital library requirements for knowledge based data processing:

Digital library requirements for knowledge structuring and management:

Digital library requirements for access to knowledge structures:

Communities involved

NKOS: Networked Knowledge Organization Systems

   Works on content standard for describing networked knowledge organization systems. Projects include development of a model for a protocol for NKOS query and response. NKOS develops cooperation between researchers and developers who are creating interactive knowledge organization systems over the web. NKOS has held three previous workshops in the USA at ACM DL conferences – this is the first European workshop on the topic.

IMesh: International Collaboration on Internet subject gateways

The NORDIC Metadata Projects

MODELS (MOving to Distributed Environments for Library Services) Terminology Workshop

The topic is relevant to digital library, museum, archives, and cultural heritage communities, geo-spatial research, systems for geo-referencing. Related topics have been/are addressed in:

Expected participants

Workshop organizers (short bios)

Martin Doerr studied mathematics and physics from 1972-1978 and holds a PhD in experimental nuclear physics from the University of Karlsruhe, Germany. His industrial experience was the successful product development of a multiprocessor operating system at Bruker, Karlsruhe, Germany, from 1984-1990. From 1990 he is a Senior Researcher at FORTH.  He has developed the Semantic Index System, a semantic network knowledge base, and the SIS-TMS, an innovative system enabling the management of multiple thesauri and cross-concordances, to product level as project leader. He is a member of the CIDOC Documentation Standards Group. He has participated in a responsible role, besides others,  in the AQUARELLE and Term-IT projects. His interests are ontology-driven systems, cultural data models and terminology management.

Traugott Koch is Senior librarian at NetLab, Lund University, Sweden and the Department of Development & IT at the Technical University of Denmark. In 1998 he was Visiting Distinguished Scholar at OCLC, Office of Research and Special Projects. He is a member of several international committees, including the Advisory Committee of the Dublin Core Initiative; the Editorial Board of Ariadne; the BIOME medical hub within the UK Resource Discovery Network; the Program Committee of DC-7, The 7th Dublin Core Metadata Workshop, Frankfurt am Main. His areas of interest include digital libraries, internet indexing and search services, knowledge organization, classification and indexing (thesauri), metadata, Dublin Core, quality controlled subject gateways. EU Projects he is currently working on include DESIRE and DESIRE II, RENARDUS, EULER, along with the NORDIC METADATA and NISBIG projects.

Douglas Tudhope is a senior lecturer in the School of Computing at the University of Glamorgan, Wales, UK and is the Editor of the New Review of Hypermedia and Multimedia. He teaches multimedia and leads the Hypermedia Research Unit at Glamorgan which has been active in the area of knowledge-based hypermedia systems since 1991, with publications in the areas of hypermedia, information science and cultural heritage. The research unit specialises in the application area of cultural heritage and Tudhope is currently directing an EPSRC funded research project in collaboration with the UK Science Museum, investigating the potential of faceted thesauri in retrieval with a view to widening access to digital collections.

Repke de Vries participates in the NIWI Research Programme 2000 - 2004: "Exploring the future of information and communication in research". In this programme he researches new information environments. The Netherlands Institute for Scientific Information Services is part of the Royal Dutch Academy of Arts and Sciences and has besides these new research activities, a long tradition in digitization, digital preservation, data archiving, document delivery and diverse other electronic information services. De Vries previously worked nationally and internationally in data archiving and before joining the research programme, participated in digital libray design and usability testing at NIWI. Part of this testing involved web based thesaurus supported information searching in NIWI databases.