期刊名称：Conference on European Chapter of the Association for Computational Linguistics (EACL)
出版年度：2011
卷号：2011
出版社：ACL Anthology
摘要：Via an oracle experiment, we show that the
upper bound on accuracy of a CCG parser
is significantly lowered when its search space
is pruned using a supertagger, though the supertagger
also prunes many bad parses. Inspired
by this analysis, we design a single
model with both supertagging and parsing features,
rather than separating them into distinct
models chained together in a pipeline.
To overcome the resulting increase in complexity,
we experiment with both belief propagation
and dual decomposition approaches to
inference, the first empirical comparison of
these algorithms that we are aware of on a
structured natural language processing problem.
On CCGbank we achieve a labelled dependency
F-measure of 88.8% on gold POS
tags, and 86.7% on automatic part-of-speeoch
tags, the best reported results for this task.
