Departmental Papers (CIS)

Date of this Version


Document Type

Journal Article


Suggested Citation:
Hockenmaier, J. and Steedman, M. (2007). CCGbank: A Corpus of CCG Derivations and Dependency Structures Extracted from the Penn Treebank. Computational Linguistics. Vol. 33(3). p. 355-396.

© 2007 Massachusetts Institute of Technology Press


This article presents an algorithm for translating the Penn Treebank into a corpus of Combinatory Categorial Grammar (CCG) derivations augmented with local and long-range word–word dependencies. The resulting corpus,CCGbank,includes 99.4% of the sentences in the Penn Treebank. It is available from the Linguistic Data Consortium,and has been used to train widecoverage statistical parsers that obtain state-of-the-art rates of dependency recovery.

In order to obtain linguistically adequate CCG analyses,and to eliminate noise and inconsistencies in the original annotation,an extensive analysis of the constructions and annotations in the Penn Treebank was called for,and a substantial number of changes to the Treebank were necessary. We discuss the implications of our findings for the extraction of other linguistically expressive grammars from the Treebank,and for the design of future treebanks.



Date Posted: 02 June 2011

This document has been peer reviewed.