Posts Tagged ‘theory’

Using Graph transformation for Collaborative Ontology Evolution

October 16, 2007

De Leenheer, P. and Mens, T. (2007) Using Graph transformation for Collaborative Ontology Evolution. Proc. of the Third International Symposium on Applications of Graph Transformation with Industrial Relevance (AGTIVE 2008) (Kassel, Germany), LNCS 5088, Springer.changedifftosibling

In collaborative ontology engineering, contexts are key to manage the complexity of different dependency types between ontological artefacts. Instead of being frustrated by out-of-control evolution processes, proper context dependency management will allow human experts to focus on the meaning interpretation and negotiation processes. This requires support for the detection and resolution of meaning ambiguities and conflicts. In this article, we explore to which extent the theory of graph transformation can be used to support this activity. More specifically, we propose the use of critical pair analysis as a formal means to analyse conflicts between ontologies that are evolving in parallel. We illustrate this with an example from a realistic case study.

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Context Dependency Management in Ontology Engineering: a Formal Approach

June 12, 2007

jods_viii_deleenheer_fig1A viable ontology engineering methodology requires supporting domain experts in gradually building and managing increasingly complex versions of ontological elements and their converging and diverging interrelationships. Contexts are necessary to formalise and reason about such a dynamic wealth of knowledge. However, context dependencies introduce many complexities. In this article, we introduce a formal framework for supporting context dependency management processes, based on the DOGMA framework and methodology for scalable ontology engineering. Key notions are a set of context dependency operators, which can be combined to manage complex context dependencies like articulation, application, specialisation,
and revision dependencies. In turn, these dependencies can be used in context-driven ontology engineering processes tailored to the specific requirements of collaborative communities. This is illustrated by a real-world case of interorganisational competency ontology engineering.

De Leenheer, P., de Moor, A., and Meersman, R. (2007) Context Dependency Management in Ontology Engineering: a Formal Approach. Journal on Data Semantics VIII, LNCS 4380, Springer-Verlag, pp. 26-56.

Disambiguation of Natural-language Terms in Business Semantics Engineering

July 10, 2005

De Leenheer, P. and de Moor, A. (2005) Context-driven Disambiguation in Ontology Elicitation. In Shvaiko P. & Euzenat J.,(eds.), Context and Ontologies: Theory, Practice and Applications, AAAI Technical Report WS-05-01 (Pittsburgh, Pennsylvania), AAAI Press, pp. 17–24.

dogma_method

Illustration of the two levels in DOGMA ontology: on the left -- the lexical level, lexons are elicited from various contexts. On the right, there is the conceptual level consisting of a concept definition server. The meaning ladder in between illustrates the articulation of lexical terms into concept definitions.

Ontologies represent rich semantics in a lexical way. Lexical labels are used to identify concepts and relationships, though there is no bijective mapping between them. Phenomenons such as synonyms and homonyms exemplify this, and can result in frustrating misunderstanding and ambiguity. In the elicitation and application of ontologies, the meaning of the ontological knowledge is dependent on the context. We consider the role of context in ontology elicitation by introducing context in a concept definition server for ontology representation. We also adopt other features of context found in literature, such as packaging of knowledge, aligning elements of different contexts, and reasoning about contexts. Finally, we illustrate context-driven ontology elicitation with a real world case study.

This paper was further extended in Journal of Data Semantics. See my related blog in this. In our business semantics management approach, disambiguation forms an important but difficult exercise during the consolidation activities.