tailieunhanh - Báo cáo khoa học: "Some Comments on Algorithm and Grammar in the Automatic Parsing of Natural Languages"

The purpose of this paper is to examine the oft-repeated assertion regarding the efficiency of a "simple parsing algorithm" combinable with a variety of different grammars written in the form of appropriate tables of rules. | Mechanical Translation and Computational Linguistics March 1966 Some Comments on Algorithm and Grammar in the Automatic Parsing of Natural Languages by Paul L. Garvin Bunker-Ramo Corporation Canoga Park California The purpose of this paper is to examine the oft-repeated assertion regarding the efficiency of a simple parsing algorithm combinable with a variety of different grammars written in the form of appropriate tables of rules. The paper raises the question of the increasing complexity of the tables when more than the most elementary natural-language conditions are included as well as the question of the ordering of the rules within such non-elementary tables. Some conclusions are presented. 1. Two basic approaches can be singled out in the automatic parsing of natural languages. These are here called bipartite and tripartite respectively. In the bipartite approach the parsing program consists of two basic portions a machine dictionary which contains grammar codes for each entry and a recognition algorithm based on a grammar of the source language the grammar is here in fact written into the algorithm. The tripartite approach is based on a strict separation of grammar and algorithm the parsing program here consists of three basic portions the machine dictionary with grammar codes a stored grammar and a parsing algorithm which utilizes the codes furnished by the dictionary and applies the grammar. The purpose of this paper is to examine the validity of the frequently repeated contention that the tripartite approach consisting in the separation of algorithm and grammar is particularly desirable in automatic-parsing programs. This examination will be restricted to the area of automatic parsing of natural languages with particular attention to the parsing problems encountered in machine translation. It must be noted at the outset that in this author s opinion the aim of the automatic-parsing component of a machine-translation program is the adequate .