PACLIC 28!358 An Example-Based Approach to Difficult Pronoun Resolution

AWinograd schema is a pair of twin sentences containing a referential ambiguity that is easy for a human to resolve but difficult for a com-puter. This paper explores the characteristics of world knowledge necessary for resolving such a schema. We observe that people tend to avoid ambiguous antecedents when using pro-nouns in writing. We present a method for au-tomatically acquiring examples that are simi-lar to Winograd schemas but have less ambi-guity. We generate a concise search query that captures the essential parts of a given source sentence and then find the alignments of the source sentence and its retrieved examples. Our experimental results show that the exist-ing sentences on the Web indeed contain in-stances of world knowledge useful for difficult pronoun resolution.