Computational Complexity of Probabilistic Disambiguation by means of TreeGrammars
Abstract
This paper studies the computational complexity of disambiguation under probabilistic treegrammars and contextfree grammars. It presents a proof that the following problems are NPhard: computing the Most Probable Parse (MPP) from a sentence or from a wordgraph, and computing the Most Probable Sentence (MPS) from a wordgraph. The NPhardness of computing the MPS from a wordgraph also holds for Stochastic ContextFree Grammars. Consequently, the existence of deterministic polynomialtime algorithms for solving these disambiguation problems is a highly improbable event.
 Publication:

arXiv eprints
 Pub Date:
 June 1996
 arXiv:
 arXiv:cmplg/9606019
 Bibcode:
 1996cmp.lg....6019S
 Keywords:

 Computer Science  Computation and Language
 EPrint:
 6 pages. To appear in COLING 1996