1. A method for improving performance of a speech recognition system comprising: operating a processor to determine a performance of the system based on either recognition of instances of a word or recognition of instances of various words among a set of words, and determining a corrective action based on the performance, to improve the performance.
24. The method of claim 1 , wherein the performance is based on an error rate comprising: a substitution rate at which the word an instance of the word or one of the various words is incorrectly recognized as another word, when comparing a hypothesis generated by the system to an expected response.