2 Specifically, this article describes all the as-yet-unpublished details and features of Collins' model and some analysis of the effect of these features with respect to parsing performance, as well as some comparative analysis of the effects of published features.
an interesting modification to the standard beam in Collins' parser is that for chart items representing NP or NP-a derivations with more than one child, the beam is expanded to be 10 4 • e 3 .