9. The computer-readable memory device of claim 8 , wherein the instructions, when executed on the processor, further cause the device to, upon identifying a failure while executing the action for the high-ranking dialogue hypothesis, report to the user an action error indicating the failure of the action.
9. The computer-readable memory device of claim 8 , wherein the instructions, when executed on the processor, further cause the device to, upon identifying a failure while executing the action for the high-ranking dialogue hypothesis, report to the user an action error indicating the failure of the action. 10. The computer-readable memory device of claim 9 , wherein the instructions, when executed on the processor, further cause the device to: upon receiving an expression of the dialogue, evaluate the expression of the dialogue according to an expression evaluator to generate at least one dialogue hypothesis involving the expression; and upon identifying a failure to parse the expression of the dialogue according to the expression evaluator, report to the user a parsing error indicating the failure to parse the expression of the dialogue, where the parsing error is different than the action error.