Leveraging back-off grammars for authoring context-free grammars

摘要

A system and method of refining context-free grammars (CFGs). The method includes deriving back-off grammar (BOG) rules from an initially developed CFG and utilizing the initial CFG and the derived BOG rules to recognize user utterances. Based on a response of the initial CFG and the derived BOG rules to the user utterances, at least a portion of the derived BOG rules are utilized to modify the initial CFG and thereby produce a refined CFG. The above method can carried out iterativey, with each new iteration utilizing a refined CFG from preceding iterations.

主权项

1. A method of refining a context-free grammar, the method comprising:
generating backoff grammar rules from rules of an initial context-free grammar, each backoff grammar rule being generated based on at least one keyword identified from the initial context-free grammar; and recursively modifying the initial context-free grammar using a computer processing unit, wherein recursively modifying comprises:
obtaining a relined context-free grammar by modifying the initial context-free grammar,during a first iteration, based at least in part on recognition of utterances using the backoff grammar rules;determining a recognition efficiency of the refined context-free grammar and the hackoff grammar rules to the utterances; andduring each of at least one additional iteration, further modifying the refined context-free grammar based at least in part on recognition of utterances using the refined context free grammar and backoff grammar rules until the refined context-free grammar and the backoff grammar rules meet a threshold level of recognition efficiency.