1. A method for conducting a user dialog via a speech-based user interface, the method comprising: providing a sequence of goal-directed auditory prompts, the sequence of goal-directed auditory prompts based upon a pre-determined user-oriented task; and if a communication error occurs, responding to the communication error by initiating an error recovery based upon a user response to the sequence of goal-directed auditory prompts; wherein the error recovery comprises providing at least one error-recovery prompt selected from a hierarchy of error-recovery prompts, the selection based upon a hierarchy of communication error types.