1998/08/31 by Mark-Jan Nederhof, Giorgio Satta
Computer Science · #cmp-lg #cs.CL
published as AI*IA 97: Advances in Artificial Intelligence, 5th Congress of the Italian Association for Artificial Intelligence, LNAI 1321, Springer Verlag, pages 84-95, 1997. · 12 pages, 1 Postscript figure, uses psfig.tex and llncs.sty
arxiv created 1998/08/31 · arxiv updated 2009/11/30
The Earley algorithm is a widely used parsing method in natural language processing applications. We introduce a variant of Earley parsing that is based on a ``delayed'' recognition of constituents. This allows us to start the recognition of a constituent only in cases in which all of its subconstituents have been found within the input string. This is particularly advantageous in several cases in which partial analysis of a constituent cannot be completed and in general in all cases of productions sharing some suffix of their right-hand sides (even for different left-hand side nonterminals). Although the two algorithms result in the same asymptotic time and space complexity, from a practical perspective our algorithm improves the time and space requirements of the original method, as shown by reported experimental results.