1. A computer-implemented dialog system training environment, comprising: a processor to execute components of a dialog system; a memory coupled to the processor; a user simulator that during the dialog system training provides at least one text to speech training output associated with an utterance, the output having variable qualities; and a dialog system that comprises: a speech model having a plurality of modifiable speech model parameters, the speech model receives the at least one text to speech training output as a speech model input related to the utterance and produces related speech model output features; a dialog action model having a plurality of modifiable dialog action model parameters, the dialog action model receives the related speech model output features from the speech model and produces related output actions, the plurality of modifiable speech model parameters, the plurality of modifiable dialog action model parameters, or a combination thereof, are based, at least in part, upon the utterance, the action taken by the dialog action model, or a combination thereof; and the dialog system identifies the utterance that is in need of clarification by initiating a repair dialog, wherein the utterance associated with the repair dialog is identified includes: determining what states of the repair dialog are reached from other states, the dialog system learns which states to go to when observing an appropriate speech and dialog features by trying all repair paths using the user simulator where a user's voice is generated using various text-to-speech (TTS) engines at adjustable levels; and determining which states of the repair dialog are failures or successes.