During any kind of information retrieval dialog, the repetition of parts of information just given by the dialog partner can often be observed. As these repetitions are usually elliptic, the intonation is very important for determining the speakers intention. In this paper prototypically the times of day repeated by the customer in train table inquiry dialogs are investigated. A scheme is developed for the officers reactions depending on the intonation of these repetitions; it has been integrated into our speech understanding and dialog system EVAR (cf. [6]). Gaussian classifiers were trained for distinguishing the dialog guiding signals confirmation, question and feedback; recognition rates of up to 87.5% were obtained
