1. Using XSLT for Interoperability: DOE and The Traveling Domain Experiment Monday 20 th of October, 2003 Antoine Isaac, Raphaël Troncy and Véronique Malaisé 2nd International Workshop Evaluation of Ontology-based Tools (EON2003)

2. 10/20/2003 Raphaël Troncy - EON'20031 Agenda The DOE tool and its methodology The choice of XSLT stylesheets for exchanging ontology models The experiment protocol –circular transformation (DOE → others → DOE) with RDFS as exchange language –circular transformation (DOE → others → DOE) with OWL as exchange language Conclusion Suggestion for further experiments

3. 10/20/2003 Raphaël Troncy - EON'20032 DOE: methodology [Bachimont et al., EKAW'02] A linguistics-grounded semantic commitment Classical formal specification process

4. 10/20/2003 Raphaël Troncy - EON'20033 DOE: methodology implementation Writing of differential principles according to differential semantics Formal definition of concepts and relations, specification of their arity and domains, introduction of individuals Export into commonly-used ontology languages Formalization step Operationalization step DOE: help for taxonomy structuring The ontology has to be more formalized: using other editors (Protégé-like) Export mechanisms are a necessity

5. 10/20/2003 Raphaël Troncy - EON'20034 DOE and the travel ontology

6. 10/20/2003 Raphaël Troncy - EON'20035 Using XSLT for the import/export Most proposed languages for encoding ontologies are based on XML XSLT is meant to transform an XML document into another one XSLT seems to be adapted to perform the transformations of XML ontologies from one representation language to another

7. 10/20/2003 Raphaël Troncy - EON'20036 The experiment protocol DOE RDFS OWL Protégé 2000 OilEd OntoEdit WebODE XSLT

8. 10/20/2003 Raphaël Troncy - EON'20037 Interoperability via RDFS (1/3) DOE  { Protégé, OilEd, OntoEdit } Our model is simple to export –Structured textual information, exported in comments –Few formal features (multi-hierarchies, individuals, domain and range assignment for relations)  a model close to RDFS Satisfactory results –Everything is quite well imported by others editors –Problems with Dublin Core Metadata (can be an important issue !)

9. 10/20/2003 Raphaël Troncy - EON'20038 Interoperability via RDFS (2/3) { Protégé, OilEd, OntoEdit, WebODE }  DOE RDFS language has multiple syntax –RDFS abbreviated syntax vs RDF non- abbreviated one: –Using rdfs:label or rdf:about to name a resource AirbusPlane

10. 10/20/2003 Raphaël Troncy - EON'20039 Interoperability via RDFS (3/3) { Protégé, OilEd, OntoEdit, WebODE }  DOE XSLT makes it tedious to deal with every possible serialization –multiplication of tests, namespace treatment Tools fail at exporting all information –DC metadata, comments, instances –add by hand the XML encoding in some cases The ontology core (concept and relation hierarchies, domains assignments) is imported  the loop is a success with RDFS

11. 10/20/2003 Raphaël Troncy - EON'200310 Interoperability via OWL (1/3) DOE  { Protégé, WebODE } Only a limited subset of OWL is concerned Quite a success, but… –Protégé OWL plug-in: individuals have to be declared using the Protégé namespace strict XML naming convention –WebODE: individuals are not imported

12. 10/20/2003 Raphaël Troncy - EON'200311 Interoperability via OWL (2/3) { Protégé, OilEd, WebODE }  DOE Similar problems:......

13. 10/20/2003 Raphaël Troncy - EON'200312 Interoperability via OWL (3/3) { Protégé, OilEd, WebODE }  DOE Moreover, two possible syntaxes: –OWL Presentation Syntax : exported but not imported –OWL Exchange Syntax (RDF-XML): DOE does not import instances … and OilEd mixes them Similar treatment difficulties: here again, it is necessary to deal with every possibility to import ontologies A little part of OWL expressiveness is used  the loop is more or less made with OWL

14. 10/20/2003 Raphaël Troncy - EON'200313 Summary Some preliminary modifications have to be done sometimes: –XML string encoding info, special caracters elimination, initiate-level namespace manipulation Ontology vocabulary elements (concepts, relations, instances): –wholly OK Formal definition: –OK, for what concerns the limited information that had to be exported and imported Differential definitions (introduced by our methodology): –exported and imported in unstructured comments Dublin Core Metadata ignored

15. 10/20/2003 Raphaël Troncy - EON'200314 Conclusion The model of DOE is simple so ontologies can be easily exported to other environments XSLT enables satisfying exports to other ontological frameworks Import mechanism faces more problems linked with: –theoretical considerations (weak formal expressiveness) –Implementation shortfalls (XSLT limits) –Semantic Web standards (multiple syntaxes)  But the interoperability is quite successful  More important : the interoperability we aimed at is properly and simply dealt with

16. 10/20/2003 Raphaël Troncy - EON'200315 Proposition for further experiments The tool (and language ?) community has still work to do in order to achieve interoperability Proposition: –establish benchmarks, with every possible syntactic representation and semantics expressivity –systematize all the tests, between each environment, at the syntax level –systematize all the tests, between each environment, at the semantics level

17. 10/20/2003 Raphaël Troncy - EON'200316 DOE : Differential Ontology Editor Available for free at : http://opales.ina.fr/public/ Library of ontologies : http://opales.ina.fr/public/ontologies