Categorization is probably one of the most central areas in the study of cognition, language and information. However, there is a serious gap running through the semantic treatments of categories and concepts [3]. On one side we find the ’classical’, formal approach, based on logical considerations, that has lent itself well for computational applications. In this approach, concepts are defined in terms of necessary and sufficient conditions. On the other side is an informal approach to categorization that is usually motivated by the results of psychological experiments and that has not found its way into technologies on a large scale. Concepts here are based on prototypes, stereotypical attributes and family resemblances, which have become the hallmark of cognitive semantics. Obviously, it is important to bridge this gap, for theoretical and practical reasons.