Categories of Arguments for Correspondences. As we mentioned in Section 2, potential arguments are clearly identified and grounded on the underlying ontology language OWL. Therefore, the grounds justifying corre- spondences can be extracted from the knowledge in ontologies. This knowledge in- cludes both the extensional and intensional OWL ontology definitions. Our classifica- tion of the grounds justifying correspondences is the following: semantic (M ): the sets of models of two entities do or do not compare; internal structural (IS): two entities share more or less internal structure (e.g., the value range or cardinality of their attributes); external structural (ES): the set of relations, each of two entities have, with other entities do or do not compare; terminological (T ): the names of two entities share more or less lexical features; extensional (E): the known extension of two entities do or do not compare. These categories correspond to the type of categorizations underlying ontology match- ing algorithms [19]. In our framework, we will use the types of arguments described above as types for the V AF ; hence = M, IS, ES, T, E . Therefore, for example, an audience may spec- ify that terminological arguments are preferred to semantic arguments, or vice versa. Note that this may vary according to the nature of the ontologies being aligned. Xxxxx- tic arguments will be given more weight in a fully axiomatised ontology, compared to that in a lightweight ontology where there is very little reliable semantic information on which to base such arguments. Table 1 summarises a number of reasons capable of justifying candidate OWL ontol- ogy alignments. Therefore, the table represents an (extensible) set of argument schemes, instantiations of which will comprise AR. Attacks between these arguments will arise when we have arguments for the same mapping but with conflicting values of σ, thus yielding attacks that can be considered symmetric. Moreover, the relations in the map- pings can also give rise to attacks: if relations are not deemed exclusive, an argument against inclusion is a fortiori an argument against equivalence (which is more general).
