Automating ontology alignment evaluation

The semantic web relies on the expression of formalized knowledge on the web (in languages like RDF). Like the web, the semantic web will have to be distributed and heterogeneous. As such, the integration of resources found on the semantic web is one of its main problems. For contributing solving this problem, data is expressed in the framework of ontologies (theories describing the vocabulary used for expressing data). However, ontologies themselves can be heterogeneous and have to be reconciled.

One way to reconcile ontologies is to find the correspondences between their entities. This is called ontology matching [1] and the resulting set of correspondences is called an alignment. Ontology matching provides a set of correspondences supposed to hold between entities of two ontologies provided as input. A correspondence is defined by a relation between entities from the two ontologies (which can be classes, individuals, properties, termes or formulas involving such terms).

We have been organising for five years the Ontology Alignment Evaluation Initiative (OAEI) whose goal is the evaluation of matching systems. The evaluation of matching systems consists of providing the matchers with pairs of ontologies and comparing the result with a reference alignment. This effort will take another dimension with the more global SEALs European project that deals with evaluating semantic technologies. In that context, we want to develop a more comprehensive matcher evaluation framework encompassing:

• Test generation;
• Automatic test processing;
• Evaluation measure implementation;
• Online synthesis and reporting.

At the moment, the evaluation chain is made of manually invoked pieces of software. Thus the position has an integration aspect in which the interfaces between various tools must be carefully engineered in order to have automatic processing.

The position also has several research aspects. In particular, test generation offers the possibility to define the notion of test hardness allowing to generate tests of selected difficulty on the fly and to compare results based on the hardness of tests. Such a notion of test hardness is defined, for instance, for constraint satisfaction problems.

Evaluation measures is also a topic in which we are active and, beside implementation, more investigations are needed for obtaining practicable semantic evaluation measures that take advantage of reasonners [2,3,4].

Finally, automatic sampling of alignments could also be a useful contribution.

References:

• EXMO (http://www.inrialpes.fr/exmo)
• OAEI (http://oaei.ontologymatching.org)
• [1] Jérôme Euzenat, Pavel Shvaiko, Ontology matching, Springer, Heildelberg (DE), 2007
• [2] Marc Ehrig, Jérôme Euzenat, Relaxed Precision and Recall for Ontology Matching, in: Ben Ashpole, Jérôme Euzenat, Marc Ehrig, Heiner Stuckenschmidt (eds), Proc. K-Cap 2005 workshop on Integrating ontology, Banff (CA), pp25-32, 2005
• [3] Jérôme Euzenat, Semantic precision and recall for ontology alignment evaluation, in: Proc. 20th International Joint Conference on Artificial Intelligence (IJCAI), Hyderabad (IN), pp348-353, 2007
• [4] Jérôme David, Jérôme Euzenat, On fixing semantic alignment evaluation measures, in: Pavel Shvaiko, Jérôme Euzenat, Fausto Giunchiglia, Heiner Stuckenschmidt (eds), Proc. 3rd ISWC 2008 workshop on ontology matching (OM), Karlsruhe (DE), pp25-36, 2008

Qualification: PhD or equivalent in computer science. Knowledge in knowledge representation, ontologies or ontology matching is welcome.

Researched skills:

• Interaction with other researchers.
• Design and programming skills.
• Taste for experiments.
• Autonomous researcher.
• Writing capabilities.
• Innovative.

Hiring date: as soon as possible after May 1st.

Place of work: The position is located at INRIA Grenoble Rhône-Alpes, Montbonnot (near Grenoble, France) a main computer science research lab, in a stimulating research environment. Research will be carried out in the Exmo team under the supervision of Jérôme Euzenat. It will require the involvement of the candidate in related projects.

Duration: 12 months (extendible to longer period)

Salary: 2357 EUR/month (before charges)

Contact: For further information, contact Jerome:Euzenat#inrialpes:fr.
Some more administrative information is available (but do not hesitate to contact us any way since we are more flexible).

Procedure: Visit INRIA's presentation (including FAQ and forms).
Note that, however, the procedure can be faster if judged necessary. In addition, send the same files to the contact above.

INRIA Priority research themes:

• Designing and mastering the future network infrastructures and communication services platforms/Concevoir et maîtriser les futures infrastructures des réseaux et des services de communication;
• Developing multimedia data and multimedia information processing/Développer le traitement des informations et données multimédia.