Structural Relations - A Case Against Case

Abstract

Usually semantic parsers of NLU systems rely on some type of 'deep cases' (Riesbeck and Schank, 1976), (Trost and Steinacker, 1981) to control analysis. While we do not want to deny the advantages of such an approach (we use it ourselves), we propose to apply a different approach in order to analyse words that derive their meaning from the semantic category of their dependent constituents. The algorithm we present in this paper disambiguates such words by making use of one of the important properties of an SI-Net (Brachman,1979), the strict distinction between structure and contents of the net. Structurally all semantic relations are represented in the same way therefore we evaluate this level to find out if there is a relation between the representation of the constituents of such a word. After a link has been found its semantic interpretation is taken to be the sense of the word. Besides being used for disambiguation the algorithm is applicable to solve other problems related to parsing as well, e.g. interpretation of metaphors or problems related to resolution of definite anaphora.