Computer-aided Acquisition of Semantic Knowledge (CASK) is aimed at describing a number of semantic fields of a few European languages using data mining techniques elaborated within the framework of the new paradigm of computation known as Knowledge Discovery in Databases (KDD). CASK's motivation is to dig deeper in order to find building blocks which could be used in various sophisticated ways. The project is interdisciplinary involving scientific cooperation of experts in linguistics with information engineers. The task of linguists consists in an interactive (computer-aided) discovery of ontology-based definitions of feature structures using the SEMANA (Semantic Analyser) software which was designed especially in order to build linguistic databases with semantic knowledge.