STITCH @ CATCH
Semantic Interoperability To access Cultural Heritage
CATCH Vocabulary and alignment repository demonstrator
This page contains information on the SKOS vocabulary and alignment service that is developed for the CATCH programme.
The public version of the service is currently available at http://eculture2.cs.vu.nl:48080/vocreptags/index.jsp.
Lourens van der Meij, Antoine Isaac, Claus Zinn. A Web-based Repository Service for Vocabularies and Alignments in the Cultural Heritage Domain. Proceedings of the 7th Extended Semantic Web Conference, (ESWC 2010). Heraklion, Greece, 30 May-3 June 2010. Paper, Slides
This demonstrator aims at showing how a repository providing access to vocabularies and alignments by means of standardized web services and models (like SKOS) could facilitate inter-institution data integration and sharing.
Vocabularies such as thesauri play an important role in making Cultural Heritage material accessible, and a range of different vocabularies is used in the institutes participating in CATCH. Providing standardized access to these would allow one to develop reusable collection access components.
Also, by providing semantic alignments between vocabularies in use in different institutes, integrated access to heterogeneous collections becomes possible. For example, one can then browse from one collection to another (see our integrated browser demos).
The publicly accessible version of the repository contains SKOS versions of the following vocabularies:
There is a version with more vocabularies, and alignments between them. However, this version is not freely available, and you should should contact us to get a login/password. The vocabularies there are:
Metrics: Here are some statistics on these vocabularies.
Note that some knowledge organization systems mentioned above often contain sub-vocabularies, and are treated as concept scheme groups.
- Data access interfaces
- Web service access (using SOAP) to SKOS versions of various thesauri
and alignments between them.
- RDF snippet and JSON access to single concepts and whole vocabularies
through a "REST-like" service interface (no put, elements by means of ? instead of /).
- SKOS-inspired Java API, both for client and server usage
- the API can manage concept alignments as sets of simple SKOS matching assertions (using skos:exactMatch, skos:broadMatch, etc) but also as set of mapping resources, following the more complex and extensible format defined for the Ontology Alignment API
- Concept browsing and searching component
- Looking up concepts with labels matching a text string or regular expression
- Concept search by autocompletion
- Browsing across vocabularies using alignments
The JavaDoc of the API is accessible at http://stitch1.cs.vu.nl/catchplus/integrator/javadoc/
This service is a prototype. In particular, there are scalability issues. Due to our wish
to provide fast access, vocabularies are maintained in memory. Interesting
vocabularies are huge though: our most advanced demo uses up 6 GB of memory... The situation should be improved by exploring technological alternatives
such using database back-end and indexing.
The service is not simply a front-end to an RDF repository containing uncontrolled RDF triples. We do use RDF repositories, yet our service provides access to a simple standardized interface to (a part of) SKOS.
- Unification of vocabularies (SKOS)
- Unified access to vocabularies
- Creation and exploitation of vocabulary alignments
- Distributed web-based architecture
- Semantic "middleware"
- Publishes its own client user interface components
Position in the field of vocabulary services
A detailed comparison of our service to others has not been made yet. We intend however
to maintain a page listing comparable services.
For any question, please contact Lourens van der Meij.