Quality of mappings for data exchange applications

Research has investigated mappings among data sources under two perspectives. On one side, there are studies of practical tools for schema mapping generation; these focus on algorithms to generate mappings based on visual specifications provided by users. On the other side, we have theoretical researches about data exchange. These study how to generate a solution -- i.e., a target instance -- given a set of mappings usually specified as tuple generating dependencies. However, these two research lines have progressed in a rather independent way and we are still far away from having a complete understanding of the properties that a "good" schema mapping system should have; to give an example, there are many possible solutions for a data exchange problem. In fact, there is no consensus yet on a notion of quality for schema mappings. In this thesis, based on concepts provided by schema mapping and data exchange research, we aim at investigate such a notion. Our goal is to identify a fairly general formal context that incorporates the different mapping-generation systems proposed in the literature, and to develop algorithms, tools and methods for characterizing the quality of mappings generated by those systems.