Punctuation Normalisation for Cleaner Treebanks and Parsers

Although punctuation is pervasive in written text, their treatment in parsers and corpora is often second-class. We examine the treatment of commas in CCGbank, a wide-coverage corpus for Combinatory Categorial Grammar (CCG), reanalysing its comma structures in order to eliminate a class of redundant rules, obtaining a more consistent treebank. We then eliminate these rules from C&C, a wide-coverage statistical CCG parser, obtaining a 37% increase in parsing speed on the standard CCGbank test set and a considerable reduction in memory consumed, without affecting parser accuracy.