What grammars tell us about corpora: the case of reduced relative clauses
Paola Merlo, Suzanne Stevenson · 1998
We present a large (65 million words of Wall Street Journal) and in-depth corpus study of a particular syntactic ambiguity to investigate (1) to what extent the structure of a grammar is reflected in a corpus, and (2)how probability functions defined according to a grammar fit independently established measures of syntactic disambiguation preference. We look at the well-known case of the ambiguity be- tween a main clause and reduced relative con- struction. We measure the probability distributions of several linguistic features (transitivity. tense. voicc) over a sample of optionally intransitive verbs. In agreement with recent resuits on parsing with lexicalised probabilistic grammars (Collins, 1997; Srinivas, 1997), we find that statistics over lexical. opposed to structural. features best correspond to human iutuitive judgments and to experimental findings. These results are enlightening to investigate novel uses of corpora, by assessing the portability of statistics across tasks, and by det. cnnining what is needed for useful syntactic annotation of corpora.