| Hi-index | 0.00 |
Currently, the TRAINS dialog system uses a more or less standard chart parser as the interface between the text of the dialog and the rest of the dialog processing system. However, traditional chart parsers are not well equipped to handle dialogs because dialog constituents can be discontinuous, with interspersed acknowledgments, editing terms, repairs, etc. This paper proposes some modifications of the current TRAINS parser enabling it to handle discontinuous dialog structure. The representation of a dialog is still superficially hierarchical (rather than consisting of interleaved structures). This is made possible by two devices: one is to accommodate repairs (e.g., to uh .. to Corning) through explicit grammar rules; the other is to accommodate mid-sentence acknowledgments (e.g., okay), editing terms (e.g., uh), etc. as ``trailers" attached to lexical items. We show how this works on a simple sample dialog. Because allowing for repairs and interruptions introduces much ambiguity, we also discuss some initial disambiguation techniques.