Learning syntactic patterns for automatic hypernym discovery

Abstract

We present a new algorithm for learning hypernym (is-a) relations from text, a key problem in machine learning for natural language understanding. This method generalizes earlier work that relied on hand-built lexico-syntactic patterns by introducing a general-purpose formalization of the pattern space based on syntactic dependency paths. We learn these paths automatically by taking hypernym/hyponym word pairs from WordNet, finding sentences containing these words in a large parsed corpus, and automatically extracting these paths. These paths are then used as features in a high-dimensional representation of noun relationships. We use a logistic regression classifier based on these features for the task of corpus-based hypernym pair identification. Our classifier is shown to outperform previous pattern-based methods for identifying hypernym pairs (using WordNet as a gold standard), and is shown to outperform those methods as well as WordNet on an independent test set.