Building an Ontological Base for Experimental Evaluation of Semantic Web Applications Peter Bartalos, Michal Barla, Gyorgy Frivolt, Michal Tvarožek, Anton Andrejko, Mária Bieliková and Pavol Návrat Institute of Informatics and Software Engineering Faculty of Informatics and information Technologies Slovak University of Technology in Bratislava

Motivation Semantic Web applications Experimental Evaluation (SWEE) –Semantic annotation of the information –Searching in semantic information space AKTORS Knowledge Web On-To-Knowledge NAZOU – job offers (nazou.fiit.stuba.sk)nazou.fiit.stuba.sk Tools for acquisition, organization and maintenance of knowledge in an environment of heterogeneous information resources MAPEKUS – scientific publication (mapekus.fiit.stuba.sk)mapekus.fiit.stuba.sk Modeling and Acquisition, Processing and Employing Knowledge About User Activities in the Internet Hyperspace Demand for well-built large scale ontologies with specific properties Filling the ontology with instances (not it’s creation) – building the A-box

Outline Approaches to ontological base creation Method for ontological test base building Evaluation Conclusions

Filling the ontology with instances Manual approaches Automatic approaches

Generic ontology editors Understand the generic structure of the ontology Immediately usable Domain independent Insufficient validation and user comfort Suitable for experts (ontology engineers)

Generic ontology editors

Specialized ontology editors Freedom in adjusting to a given ontology and user requirements Sophisticated validation based on the knowledge of the ontology Development and maintenance costs Coupled to a ontology Suitable also for non-experts

Specialized ontology editors JOE – Job Offer Editor

Wrappers Parse Web pages and produce structured output Need well structured pages Do not need a human involvement Significant amount of acquired data Development and maintenance costs

Generators Reusing the already existing data Increase the size of the ontological base Instances of desired properties Development and maintenance costs Meaningfulness of the data

Approaches to Ontological Base Creation Different approaches have different benefits and disadvantages They support each other They can be adjusted –Invested time –Development of tools

Method of Ontological Base Creation Specification of the requirements for the ontology –Amount of data –Range of properties of the instances –Instance detail –Quality Analysis of the domain and information sources Generally no approach can separately satisfy the requirements Adjusting the manual and automatic approaches

Method of Ontological Base Creation Web ) 3Wrappers SWEEOntology 1 )Generic editor 2)Specialized 4)Generators

Satisfaction of the requirements to ontological data

Generic editor

Satisfaction of the requirements to ontological data Generic editor Specialized editor

Satisfaction of the requirements to ontological data Generic editor Specialized editor Wrappers

Satisfaction of the requirements to ontological data Generic editor Specialized editor Wrappers Generators

Evaluation of the method NAZOU (nazou.fiit.stuba.sk)nazou.fiit.stuba.sk –Ontology consists of 740 classes (670 belong to taxonomies) –All approaches used MAPEKUS (mapekus.fiit.stuba.sk)mapekus.fiit.stuba.sk –Ontology consists of 390 classes (360 belong to taxonomies) –Only one approach used

Conclusions Solution for building ontologies for semantic Web application experimental evaluation Tunable method based on different approaches of ontology instance creation Evaluated in the domain of job offers and scientific publication Developed two SWEE ontologies –Job offer ontology –Publication metadata ontology