A Framework for Incremental Syntactic Tree Formation

Abstract

A syntactic tree formation system is described for use in incremental sentence generators, i.e. generators which allow for parallel planning of conceptual content and linguistic expression. The system achieves full generality in the sense that (1) all forms of incremental production (upward expansions, downward expansions, and insertions) are covered, and (2) branches of a syntactic tree are grown in a maximally independent way (3) while at the same time grammaticality of the utterance as a whole can be maintained (aside from 'syntactic deadlocks'). The tree formation system is called Incremental Grammar (IG). Two novel ideas are the use of node-arc-node segments as elementary building blocks (e.g S-subject-NP, S-object-S, NP-head-N, PP-object-NP), and the introduction of feature matrices associated with segments rather than with nodes.