Incremental Generation with Categorial Grammar and HPSG

The paper describes an approach to generation with HPSG based on earlier work with categorial grammar. We show that a non-incremental generation algorithm for categorial grammar and indexed logical form can easily be adapted for use with HPSG and MinimalRecursion Semantics. However, if the algorithm is modiied to support incremental generation, diierent notions of syntactic constituency become signiicant. Incomplete utterances which can be valid constituents in categorial grammar are non-constituents in HPSG. Nevertheless this apparent weakness in HPSG is not real, as the incomplete utterances can be produced from active edges in the chart. In fact, it is information structure, not syntactic structure, which drives incremental utterances.