Indexing methods for efficient parsing

This paper presents recent developments of an indexing technique aimed at improving parsing times. Although several methods exist today that serve this purpose, most of them rely on statistical data collected during lengthy training phases. Our goal is to obtain a reliable method that exhibits an optimal efficiency/cost ratio, without lengthy training processes. We focus here on static analysis of the grammar, a method that has unworthily received less attention in the last few years in computational linguistics. The paper is organized as follows: first, the parsing and indexing problem are introduced, followed by a description of the general indexing strategy for chart parsing; second, a detailed overview and performance analysis of the indexing technique used for typed-feature structure grammars is presented; finally, conclusions and future work are outlined.