Can Subcategorization Help a Statistical Dependency Parser?

Today there is a relatively large body of work on automatic acquisition of lexicosyntactical preferences (subcategorization) from corpora. Various techniques have been developed that not only produce machinereadable subcategorization dictionaries but also they are capable of weighing the various subcategorization frames probabilistically. Clearly there should be a potential to use such weighted lexical information to improve statistical parsing, though published experiments proving (or disproving) such hypothesis are comparatively rare. One experiment is described in (Carroll et al., 1998) — they use subcategorization probabilities for ranking trees generated by unification-based phrasal grammar. The present paper, on the other hand, involves a statistical dependency parser. Although dependency and constituency parsing are of quite a different nature, we show that a subcategorization model is of much use here as well.