8. A system comprising: a processor configured to perform speech recognition; and a computer-readable storage medium having instruction stored which, when executed by the processor, cause the processor to perform operations comprising: identifying, based on past interactions with a user participating in a dialog with a speech dialog system, an adaptation schema which, when applied to a speech recognition model, increases a likelihood the speech recognition model will recognize misrecognized speech from the user relative to an unadapted speech recognition model; determining that the user has previously repeated speech inputs based on interactions with the user prior to initiating the dialog, to yield a determination; and adapting, based on the determination, the speech recognition model using the adaptation schema before an expected repeat speech input, wherein adapting the speech recognition model further comprises modifying an acoustic model, a language model, and a semantic model.
11. The system of claim 8 , the computer-readable storage medium having additional instructions stored which, when executed by the processor, cause the processor to perform operations comprising retaining an unmodified speech recognition model in parallel with an adapted speech recognition model.