Participants of this task are expected to align two Dutch thesauri used to index books from two collections held by the National Library of the Netherlands (KB). The required alignments links are inspired by the SKOS vocabulary. Results have been evaluated by members of the STITCH project and thanks to an application-specific gold standard.
This task reiterates the OAEI 2007 Library track.
Results have been submitted. Evaluation is available here.
KB maintains two big collections: the Deposit Collection, containing all the Dutch printed publications (one million items), and the Scientific Collection, with about 1.4 million books mainly about the history, language and culture of the Netherlands.
Each collection is described according to its own indexing system and conceptual vocabulary. On the one hand, the Scientific Collection is described using the GTT, a huge vocabulary containing 35,000 general concepts ranging from Wolkenkrabbers (Sky-scrapers) to Verzorging (Care). On the other hand, the books contained in the Deposit Collection are mainly indexed against the Brinkman thesaurus, containing a large set of headings (more than 5,000) that are expected to serve as global subjects of books. Both thesauri have similar coverage (there are more than 2,000 concepts having exactly the same label) but differ in granularity.
For each concept, the thesauri provide the usual lexical and semantic information: preferred labels, synonyms and notes, broader and related concepts, etc. The language of both thesauri is Dutch, but a quite substantial part of Brinkman concepts (around 60%) come with English labels. For the purpose of the alignment, the two thesauri have been represented according to the SKOS model, which provides with all these features. But an OWL version is available (see the appendix for more details).
The goal of the task is to find semantic links between the concepts contained by these GTT and Brinkman thesauri.
Note that the two collections described with the GTT and Brinkman thesaurus are overlapping: some books are hence described by the two thesauri. This year, book descriptions will be made available to participants, so as to enable the use of extension-based alignment techniques.
The expected alignments shall come in the format defined for the Ontology Alignment API.
As the context of the task is clearly thesaurus-based information systems,
the alignment links to be produced shall be compatible with standard
thesaurus semantic links. Especially expected are alignment links found in
the (new) SKOS vocabulary
http://www.w3.org/2008/05/skos#, referred to as
skos:exactMatch, which denotes equivalence between two concepts;
skos:narrowMatch, denoting hierarchical generalization and specialization;
skos:relatedMatch, denoting general association.
Note that other semantic relations found in the former SKOS mapping
http://www.w3.org/2004/02/skos/mapping#,referred to as
skosm:) are not allowed:
skosm:majorMatch. It is however
possible to use classes of SKOS mapping that enable to map defined concepts,
even though not all be evaluated:
skosm:OR, denoting intersection and union of concepts, will be evaluated;
skosm:NOTwill not be evaluated.
It is also possible to handle alignment results in the form of OWL
owl:equivalentClass,...). But these will be interpreted
according to the rules presented in the appendix on
Note on alignment cardinality and confidence measure:
Evaluation of the alignments will be done by members of the STITCH team with the help of domain experts. A special attention will be given to application relevance. As for last year, criteria for evaluation will be chosen according to specific application scenarios like unified thesaurus design or book re-annotation.
Due to the size of the vocabulary, only sample evaluation may be carried out for some scenarios. The modality of this sample evaluation will be determined later, depending for example on the number of participants.
Please notice that this e-mail process is not only expected to ensure compliance with IP situation. It will also help us to keep contact with participants, for instance if a new version of the data is produced, after a complaint by a participant.
Stefan Schlobach (VU) Claus Zinn (MPI) have helped the scientific organization of the track. Yvonne van der Steen, Irene Wolters, Maarten van Schie, Erik Oltmans and Johan Stapels have given crucial help on the KB side.
Please send any questions and comments to Antoine Isaac and Henk Matthezing.
In case the participants' tool cannot input or output the proposed SKOS data, OWL versions are provided, and OWL alignment relationships can be evaluated. Notice, however, that this amounts to making specific interpretations of the original data and produced alignments, and might reduce the quality of the final results.
The following conversions were made regarding the SKOS data made available for the track:
skos:Conceptare converted into instances of
skos:hiddenLabelstatements are converted to
rdfs:labelstatements, which removes the subtle distinctions that exist between these different properties (in GTT for instance, many
altLabels are not synonyms at all)
skos:notes are converted to
skos:broaderstatements are converted into
skos:relatedstatements are converted into
The following interpretations will be made of OWL data sent back by participants:
owl:Classwill be interpreted as instances of
owl:equivalentClassstatements will be interpreted as
owl:sameAs, these statements will also be interpreted as
rdfs:subClassOfstatements will be interpreted as
rdfs:seeAlsostatements will be interpreted as
skosm:OR. Disjunction-like statements (
owl:ComplementOfwhich could be interpreted as statements involving
skosm:NOT) will be ignored, as these are not evaluated.