On Contribution of Sense Dependencies to Word Sense Disambiguation

抄録

Traditionally, many researchers have addressed word sense disambiguation (WSD) as an independent classification problem for each word in a sentence. However, the problem with their approaches is that they disregard the interdependencies of word senses. Additionally, since they construct an individual sense classifier for each word, their method is limited in its applicability to the word senses for which training instances are served. In this paper, we propose a supervised WSD model based on the syntactic dependencies of word senses. In particular, we assume that strong dependencies between the sense of a syntactic head and those of its dependents exist. We describe these dependencies on the tree-structured conditional random fields (T-CRFs), and obtain the most appropriate assignment of senses optimized over the sentence. Furthermore, we incorporate these sense dependencies in combination with various coarse-grained sense tag sets, which are expected to relieve the data sparseness problem, and enable our model to work even for words that do not appear in the training data. In experiments, we display the appropriateness of considering the syntactic dependencies of senses, as well as the improvements by the use of coarse-grained tag sets. The performance of our model is shown to be comparable to those of state-of-the-art WSD systems. We also present an in-depth analysis of the effectiveness of the sense dependency features by showing intuitive examples.