An experiment with heuristic parsing of swedish

Abstract

Heuristic parsing is the art of doing parsing in a haphazard and seemingly careless manner but in such a way that the outcome is still "good", at least from a statistical point of view, or, hopefully, even from a more absolute point of view. The idea is to find strategic shortcuts derived from guesses about the structure of a sentence based on scanty observations of linguistic units in the sentence. If the guess comes out right much parsing time can be saved, and if it does not, many subobservations may still be valid for revised guesses. In the (very preliminary) experiment reported here the main idea is to make use of (combinations of) surface phenomena as much as possible as the base for the prediction of the structure as a whole. In the parser to be developed along the lines sketched in this report main stress is put on arriving at independently working, parallel recognition procedures. The work reported here is both aimed at simulating certain aspects of human language perception and at arriving at effective algorithms for actual parsing of running text. There is, indeed, a great need for fast such algorithms, e.g. for the analysis of the literally millions of words of running text that already today comprise the data bases in various large information retrieval systems, and which can be expected to expand several orders of magnitude both in importance and in size in the foreseeable future.