Paper: Grammar Specialization Through Entropy Thresholds

ACL ID P94-1026
Title Grammar Specialization Through Entropy Thresholds
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 1994

Explanation-based generalization is used to extract a specialized grammar from the original one using a train- ing corpus of parse trees. This allows very much faster parsing and gives a lower error rate, at the price of a small loss in coverage. Previously, it has been necessary to specify the tree-cutting criteria (or operationality cri- teria) manually; here they are derived automatically from the training set and the desired coverage of the specialized grammar. This is done by assigning an en- tropy value to each node in the parse trees and cutting in the nodes with sufficiently high entropy values. BACKGROUND Previous work by Manny Rayner and the author, see [Samuelsson &~ Rayner 1991] attempts to tailor an ex- isting natural-language system to a specific application domain by extract...