1. A method of enhancing performance of a natural language system employing an initial speech recognition model and an initial action classification model, said system, during operation, engaging in a plurality of transactions, said method comprising the steps of: obtaining, during the operation of said system based on the initial speech recognition model and the initial action classification model, for pertinent ones of said transactions, at least audio data and associated transaction classification data; and modifying at least one of the initial speech recognition model and the initial action classification model to obtain an iterated speech recognition model and an iterated action classification model, said modifying being based at least in part on said audio data and associated transaction classification data, so as to effect a desired change in an unisolated performance metric pertinent to performance of said natural language system