Signal-Non-Understanding (DAMSL): S explicitly indicates a problem in understanding the antecedent.OverallNegativeAutoFeedback (DIT): S wants A to know that S’s perception of the previous utterance encountered a problem.Feedback_Negative (Verbmobil): The speaker reacts to a contribution of the dialogue partner in a negative way. A FEEDBACK_NEGATIVE can signal rejection of the contents or illocution of a previous contribution or it can express an answer to a yes/no-question. (See also /OverallNegativeAutoFeedback/).