An Iterative Approach to Estimating Frequencies over a Semantic Hierarchy

Abstract

This paper is concerned with using a semantic hierarchy to estimate the frequency with which a word sense appears as a given argument of a verb, assuming the data is not sense disambiguated. The standard approach is to split the count for any noun appearing in the data equally among the alternative senses of the noun. This can lead to inaccurate estimates. We describe a reestimation process which uses the accumulated counts of hypernyms of the alternative senses in order to redistribute the count. In order to choose a hypernym for each alternative sense, we employ a novel technique which uses a 2 test to measure the homogeneity of sets of concepts in the hierarchy. 1 Introduction Knowledge of the constraints a verb places on the semantic types of its arguments (variously called selectional restrictions, selectional preferences, selectional constraints) is of use in many areas of natural language processing, particularly structural disambiguation. Recent treatments of selectional r...