But the CCG account is a competence model as well as a performance model, in that it seeks to unify category representations used in processing with learned generalizations about argument structure; whereas the model described in this paper is exclusively a performance model, allowing generalizations about lexical argument structures to be learned in some other representation, then combined with probabilistic information about parsing strategies to yield a set of derived incomplete constituents.
the model described in this paper has a freer hand to satisfy strict working memory bounds, which may not permit some of the alternative composition operations proposed in the CCG account, thought to be associated with available prosody and quantifier scope analyses.