The Río de la Plata Ontology Group

1 Research Statement

Ontologies are generally used to specify and communicate domain knowledge in a generic way. While in a formal sense "ontology" means study of concepts, the word "ontology" can be used as a concept repository about a particular area of interest. In the Computer Science area there is a well establish definition of Ontology, provided by Tom Gruber, as a formal, explicit specification of a shared conceptualization. Ontologies are very useful for structuring and defining the meaning of the metadata terms that are collected inside a domain community. They are a popular research topic in knowledge engineering, natural language processing, databases, intelligent information integration and multi-agent systems. Ontologies are also applied in the World Wide Web community where they provide the ability for making the semantics of metadata machine understandable. This vision refers also to an ontology as a conceptual model of the reality.

Nowadays, autonomously developed ontologies emerge quite naturally in different domains (health, tourism, learning, quality of services, etc.). These ontologies, each one built for different purpose, are used together in complex applications. However, how they are combined is usually hidden in the application code. The lack of an approach for explicitly expressing the way how ontologies are combined for a specific purpose, leads to think on ontology networks as a new ontology engineering concept. Currently, new approaches emerge and consider the building of ontology networks as a new development paradigm, based on the reuse and re-engineering of knowledge resources, as well as the collaborative and argumentative ontology development. This ontology network paradigm is being increasingly applied, instead of custom-building new ontologies from scratch.

This problem has been identified as an interest topic since several years as it has been shown by the WoMO (Workshop of Modular Ontology) community, who states that: “constructing large ontologies typically requires collaboration among multiple individuals or groups with expertise in specific areas, with each participant contributing only a part of the ontology. Therefore, instead of a single, centralized ontology, in most domains, there are multiple distributed ontologies covering parts of the domain. Because no single ontology can meet the needs of all users under every conceivable scenario, the ontology that meets the needs of a user or a group of users needs to be assembled from several independently developed ontology modules. Thus, in realistic applications, it is often desirable to logically integrate different ontologies, wholly or in part, into a single, reconciled ontology. Ideally, one would expect the individual ontologies to be developed as independently as possible from the rest, and the final reconciliation to be seamless and free from unexpected results. This would allow for the modular design of large ontologies and would facilitate knowledge reuse. Few ontology development tools, however, provide any support for integration, and there has been relatively little study of the problem at a fundamental level”.

Key aspects of this task are the quality design of these networked ontologies and the complete understanding of the theory underlining them in order to allow the development of a new generation of complex systems, which can make the most of the availability of reusable semantic resources.

An ontology network differs from a set of interconnected single ontologies, due to in an ontology network the meta-relationships among the different ontologies involved are explicitly expressed.

The design of ontology networks which modelling complex systems requires specific considerations. It is not only important to formally expressing the correspondences between the networked ontologies but also to have a theoretical approach that assures the coherence and consistency of the whole ontology network specification, such that the new knowledge inferred in the ontology network does not result in semantic contradictions with the set of axioms of each ontology. 1.1

List of the research topics pursued by the group: 1) Networked Ontologies 2) Ontology-based Multiple Domain Application Design a) Semantic Recommender System b) Educational Information Systems c) Semantic Interoperability of Health Information Systems d) Ontology-based methodology for conceptual DW Design 3) Collaborative Ontology Development a) Personal Semantic Information Management in Semantic Wikis b) Semantic Information Refactoring in Semantic Wikis

2 Brief History of the TANGO Group

The development of complex information systems, especially those involving autonomous and heterogeneous data sources, requires specification of metadata at descriptive and operational level, to guide their maintenance and evolution. Special cases of these systems are recommender systems, semantic web applications, elearning, e-health and decision support systems.

First works around these subjects at InCo has been conducted by Regina Motz since 2004. The initial goals were the design and use of ontologies for information extraction from the web [ 1-5 ] and for modeling metadata quality in e-learning [ 6 ]. Then the focus has been on its use in decisional systems [ 7 ], adaptive systems [ 8 ] and personalization [ 9,10 ].

One approach has been the analysis of theoretical problems for the use of ontologies in the acquisition and administration of the quality factors of the sources of a web data warehouse [ 11 ]. On the other hand, this approach has been complemented by the development of an ontology based methodology to assist the conceptual design of Data Warehouses [ 12 ].

In the generic scenario of exploitation of ontologies to ensure adaptive information systems, the work has been concentrated in the reuse of ontologies for managing changes in the components of a system. In this sense, a relevant topic has been the study of the use of ontologies, specifically OWL-S, for semantic web service discovery [ 13, 14 ].

In parallel, works at LIFIA group, conducted by Alicia Díaz focus on the collaborative development of ontologies. Some results in these areas are: (i) CoProtégé [ 15, 16 ], an extension of Protégé to support the collaborative development of ontologies, (ii) considering the ontology development as a collaborative knowledge building process [ 17-19 ]; and refactoring of ontologies [ 20 ]. Last two topics are study in the context of semantic wikis. In (ii), the research focuses on study how ontology emerges as result of the adding of semantic annotation of wiki pages by a community and how personal information management can be supported. In (iii), a software engineering approach it is follow to improve the collaborative design of a ontology underlined in a semantic wikis. In this work was developed a catalog of “bad smells” that can be automatically detected in the underlined ontology in a semantic wiki, and a catalog of “refactoring” to fix the bad smells. Both (ii) and (iii) are developed in the context of Semantic MediaWiki.

Since the confluence of both groups at the CYTED-SALUS project [ 21, 22 ], they begin to work together focusing on the theoretical aspects of ontology networks applied to recommender systems [ 23 ].

One of the main objectives of the TANGO group is the development of recommender systems based on ontologies that are sensitive to the context of social personal recommendation. At the same time, it is of great interest that these recommendations provide tools for reasoning about the recommendation criteria and to easily visualize and track the recommendation.

To achieve these goals, there are two case studies that are being studied: the health website recommendations [ 24 ] and a semantic educational recommender system [ 25 ].

Meanwhile, a key subject is the formalization of relationships among the networked ontologies. A primary step in this direction has been published in [ 26 ]. The main characteristics of an ontology network design are discussed in the works [ 27, 28 ] while aspects of the scope of ontologies and reasoning rules for maintaining consistency of the system are presented in [ 29, 30 ].

References

1. Matias Polero , Pablo Lopez y Rodrigo Lopez. La Intranet Semántica. Tesis/Monografía de grado, Ingeniería en Computación , UDELAR - Facultad de Ingeniería - UDeLaR. Tutor: Regina Motz. ( 2004 ).

2. Alvaro Fernandez Extracción de Información de la Web basado en Ontologías. Disertación (Maestría en Ingeniería en Computación) , UDELAR - Facultad de Ingeniería - UDeLaR. Tutor: Regina Motz. ( 2004 ).

3. Regina Motz , Jacqueline Guzmán, Claudia Deco, Cristina Bender . Applying Ontologies to Educational Resources Retrieval driven by Cultural Aspects . Journal Of Computer Science And Technology, v. 5 4 , p. 279 - 284 , ( 2005 ).

4. REGINA MOTZ ; MÓNICA MARTINEZ Ontología para criterios de clasificación . In: Workshop on Ontologies and Metamodels in Software Engineering (WOMSDE) , 2006 Florianópolis . ( 2006 ).

5. Deco , C. Refinador Semántico para Referencias Bibliográficas. Disertación (Maestría en Informática (UDELAR-PEDECIBA)) , UDELAR - Facultad de Ingeniería - UDeLaR. Tutor: Regina Motz. ( 2004 ).

6. REGINA MOTZ ; ADRIANA MAROTTA; DIEGO SASTRE Including Quality Properties into an E-Learning Ontology . In: CAISE Workshop- Semantic Web for Web Based Learning , 2005 Porto, Portugal . ( 2005 ).

7. Piqué , H. and Asiz , G. DSS basado en Ontologías . Instituto de Computación. Tesis de Grado. Tutor: F. Carpani . ( 2006 ).

8. Jacqueline Guzman Ontologias para Adaptabilidad de Sistemas de Informacion. Trabajo de Iniciación a la investigación (Ingenieria en Computacion) , UDELAR - Facultad de Ingeniería - UDeLaR. Tutor: Regina Motz. ( 2005 )

9. REGINA MOTZ; JACQUELINE GUZMAN Proceso de Reutilización de Ontologías en Sistemas de Personalización . In: Proceso de Reutilización de Ontologías en Sistemas de Personalización, Zaragoza II Congreso Espaniol de Informática. ( 2007 ).

10. Bender , C. Recuperación Personalizada desde Repositoriso de e-cursos. Disertación (Maestría en Informática (UDELAR-PEDECIBA)) , UDELAR - Facultad de Ingeniería - UDeLaR. Tutor: Regina Motz. ( 2007 ).

11. REGINA MOTZ; GUZMAN LLAMBIAS; FEDERICO TOLEDO; SIMON DE UVAROW . Learning to get the value of quality from web data . In: OTM Workshop Web Semantic & Semantics Web , Monterrey, México LNCS . ( 2008 )

12. Sebastian Gimenez , Regina Motz, Fernando Carpani, Diego Gayoso, Cecilia Colombatto: Diseño Multidimensional guiado por Ontología . CIbSE: 169 - 182 ( 2008 )

13. Janina Faggiano , Silvana Pidre y Federico Herrera Arquitectura Orientada a Servicios Semanticos . Tesis/Monografía de grado, Ingeniería en Computación , UDELAR - Facultad de Ingeniería - UDeLaR. Tutores: Regina Motz, Laura González. ( 2008 )

14. Guzmán Llambías , Regina Motz, Alvaro Rettich, Marco Scalone: Multidimensional Semantic Web Services Matching . LA-WEB: 115 - 120 . ( 2008 )

15. Diaz Alicia and Baldo Guillermo and Canals Gerome . Co-Protégé: Collaborative Ontology Building with Divergences . Seventh International Workshop on Theory and Applications of Knowledge Management (TAKMA) , September . ( 2006 )

16. A. Diaz and G. Baldo. CO-Protege: A groupware Tool for Supporting Collaborative Ontology Design and Divergence . Evento: 8th Intl. Protégé Conference , July ( 2005 ).

17. Hernán Astudillo , Víctor Codocedo, Gérome Canals, Diego Torres, Alicia Diaz, Amedeo Napoli, Alan K. Gomes , Maria Graça C. Pimentel. Combining knowledge discovery, ontologies, annotation, and semantic wikis. In press as book chapter at the Tutorial book of the Simpósio Brasileiro de Sistemas Multimedia e Web (Webmedia ), 5 -7 Octubre ( 2009 ).

18. Diego Torres, Hala Skaf-Molli, Alicia Díaz, Pascal Molli: Supporting Personal Semantic Annotations in P2P Semantic Wikis . DEXA 2009 : 317 - 331 ( 2009 )

19. Diego Toress, Hala Skaf-Molli, Alicia Diaz and Pascal Molli . Personal Navigation in Semantic Wikis . In International Workshop on Adaptation and Personalization for Web 2.0 in connection with UMAP'09 , Trento , Italy , June ( 2009 )

20. Rosenfeld M. , Fenández A. , Diaz A. Semantic Wiki Refactoring . A strategy to assist Semantic Wiki evolution Fifth Workshop on Semantic Wikis: Linking Data and People [SemWiki2010] at the 7th Extended Semantic Web Conference (ESWC) in Crete , Greece, May 31 , ( 2010 ).

21. Regina Motz , Edelweis Rohrer . Ontology design for web sites recommendation in the health area . Cadernos de Informática, v. 4 2 , p. 35 - 46 ( 2009 )

22. Díaz , A . La Ontología Salus como una red de Ontologías. Cadernos de Informática - Vol. 4 , n. 2 ( novembro ), pp 7 - 18 . - Porto Alegre : Instituto de Informática UFRGS , 2009 ; ISSN 1519- 132X ( 2009 )

23. Rohrer E. , R. Motz , A. Díaz . Web Site Recommendation Modelling Assisted by Ontologies Networks. Anais dos Workshops SALUS/CYTED-CNPq, PROSUL-CNPq AvalSaúde e SticAmSUD-CAPES ALAP . Cadernos de Informática Vol. 5 , No 1, pp 49 - 68 . ( 2010 )

24. Alicia Diaz , Regina Motz, José Valdení de Lima, Diego López. Quality Health Information Retrieval: Improving Semantic Recommender Systems with Friendsourcing . LACCIR . ( 2011 ).

25. Alicia Díaz , Regina Motz, Edelweis Rohrer, Libertad Tansini . An Ontology Network for Educational Recommender Systems . En Educational Recommender Systems and Technologies: Practices and Challenges, Eds. Olga C. Santos, Jesús G. Boticario.IGI Global, In Press. ( 2011 ).

26. Alicia Díaz , Regina Motz and Edelweis Rohrer . Making Ontology Relationships Explicit in an Ontology Network. Alicia Díaz, Regina Motz and Edelweis Rohrer . Alberto Mendelzon Workshop of Foundations of Databases and the Web ( 2011 ).

27. Rohrer E. , R. Motz and A. Díaz . Ontology-based Process for Recommending Health Web Sites . 10th IFIP WG 6 .11 Conference on e-Business, e-Services, and e-Society, I3E 2010 , Buenos Aires , Argentina, November 3- 5 , 2010 . IFIP Advances in Information and Communication Technology Vol. 341 , Springer. Cellary, W.; Estevez , E . (Eds.). ISBN: 978-3-642-16282-4 . ( 2010 )

28. Rohrer E. , A. Díaz and R. Motz . Modelling and Use of an Ontology Network for Website Recommendation Systems . Poster section of 9th edition of OnTheMove (OTM 2010 ), Crete, Greece, Oct 26 - 28 . ( 2010 ).

29. Rohrer E. , A. Díaz and R. Motz . Modeling a Web Site Quality-based Recommendation System . Accepted as full paper at iiWAS2010 , ACM Press, ISBN 978-1-4503-0421-4 . Paris, France. 8 - 10 November . ( 2010 ).

30. Edelweis Rohrer . Estudio de Metodologías de Diseño y Desarrollo de Ontologías. Aplicación a un caso de estudio de evaluación de sitios web del área salud . Disertación (Maestría en Ingeniería enComputación) , UDELAR - Facultad de Ingeniería - UDeLaR. Tutor: Regina Motz. ( 2009 )