tailieunhanh - Báo cáo khoa học: "PERSPECTIVES ON PARSING ISSUES"

Nowhere is t h e tension between the two areas of our field--computatlon and llnguistlcs--more apparent than in the issues that arise in connection with parsing natural language input. This panel addresses those issues from both computational and linguisric perspectives. Each panelist has submitted a position paper on some of the questions that appear below. The questions are loosely grouped in three sections. The first concentrates on the computational aspect, the second on the linguistic aspect, and the third on their interactions. . | PERSPECTIVES ON PARSING ISSUES Jane J. Robinson Chair Artificial Intelligence Center SRI International Nowhere is the tension between the two areas of our field computation and linguistics--more apparent than In the issues that arise In connection with parsing natural language Input. This panel addresses those issues from both computational and linguistic perspectives. Each panelist has submitted a position paper on some of the questions that appear below. The questions are loosely grouped in three sections. The first concentrates on the computational aspect the second on the linguistic aspect and the third on their interactions. A preliminary definition For purposes of providing common ground or possibly a common point of departure at the outset I will define parsing as the assigning of labelled syntactic structure to an Input by applying a grammar that defines syntactically well-formed sentences and phrases. Note that the question of whether the grammar does other things as well is left open. In this sense parsing Is distinguished from interpretation which may take many forms such as assigning representations In an unambiguous formal language and Integrating those representations into a data base or into a hearer s belief system. The questions 1. The Computational Perspective What useful purposes if any are served by distinguishing parsing from Interpretation Is computational efficiency Increased Is system building made easier Or Is an Insistence on parsing a hindrance Can we compute an interpretation better without assigning labelled syntactic structures Computational linguists using available computational equipment that Is almost exclusively serial In design have devised parsing algorithms that involve serial search. Yet it Is obvious that many parts of the parsing process could be done In parallel. How might notions of parallel processing VLSI and the like change our views on parsing What might motivate our trying to make parsing procedures simulate human .