  This paper presents an approach for the automatic acquisition of linguistic
knowledge from unstructured data. The acquired knowledge is represented in the
lexical knowledge representation language DATR. A set of transformation rules
that establish inheritance relationships and a default-inference algorithm make
up the basis components of the system. Since the overall approach is not
restricted to a special domain, the heuristic inference strategy uses criteria
to evaluate the quality of a DATR theory, where different domains may require
different criteria. The system is applied to the linguistic learning task of
German noun inflection.
