In this paper we first propose a new statistical parsing model, which is a generative model of lexicalised context-free grammar. We then extend the model to include a probabilistic treatment of both subcategorisation and wh-movement. Results on Wall Street Journal text show that the parser performs at constituent precision/recall, an average improvement of over (Collins 96). is derived from the analysis given in Generalized Phrase Structure Grammar (Gazdar et al. 95). The work makes two advances over previous models: First, Model 1 performs significantly better than (Collins 96), and Models 2 and 3 give further improvements.
