41. The apparatus of claim 25 , wherein the performance is based on an error rate comprising: a rate at which the system substitutes an instance of the word or one of he various words in the system's hypothesis for a first utterance, followed by a user repeating the first utterance in a second utterance, followed by the system recognizing and accepting the second utterance.
25. An apparatus for improving performance of a speech recognition system comprising: a processor that is configured to determine a performance of the speech recognition system based on either recognition of instances of a word or recognition of instances of various words among a set of words; the processor further configured to determine a corrective action based on the previously determined performance to improve the performance of the speech recognition system.