Ontology Alignment Overview

At present, ontologies are considered to be an appropriate solution to the problem of heterogeneity in data, since ontological methods make it possible to reach a common understanding of concepts in a particular domain. However, utilizing a single ontology is neither always possible nor recommendable, given that different tasks or different points of view usually require different conceptualizations. This can lead to the usage of different ontologies, although in some cases the different ontologies collectively might contain information that could be overlapping and possibly even contradictory. This, in turn, represents another type of heterogeneity that can result in inefficient processing or misinterpretation of data, information, and knowledge. To address this problem while at the same time insure an appropriate level of interoperability between heterogeneous systems, it is necessary to find correspondences or mappings that exist between the elements of the (different) ontologies being used. This process is known as ontology alignment. This article offers an updated overview of ontology alignment, including a detailed explanation of what alignment consists of, and how it can be achieved. First, ontologies are defined using a fusion of different interpretations. This is followed by a definition of the concept of ontology alignment and, using a simple example, some of the most commonly used alignment techniques are illustrated. Subsequently, a case is made for the importance of automating the process of ontology alignment, summarizing some of the main alignment systems currently in use. Finally, in the context of future directions, a discussion is presented of the advantages associated with integrating ontology alignment into systems that require exchanging information in an automatic fashion.