The basic techniques presented in Chap. 4 are the building blocks on which a matching solution is built. Once the similarity or (dis)similarity between ontology entities are available, the alignment remains to be computed. This involves more global treatments. In particular, the following aspects of building a working matching system are considered in this chapter:
aggregating the results of the basic methods in order to compute the compound similarity between entities (§5.2) and organising the combination of various similarities or matching algorithms (§5.1);
developing a strategy for computing these similarities in spite of cycles and non linearity in the constraints governing similarities (§5.3);
learning from data the best method and the best parameters for matching (§5.4);
using probabilistic methods to combine matchers or to derive missing correspondences (§5.5);
involving users in the loop (§5.6);
extracting the alignments from the resulting (dis)similarity: indeed, different alignments with different characteristics can be extracted from the same (dis)similarity (§5.7).