As opposed to normal data aquisition (DAQ), prompted data acquisition is the retrieval of data at discrete points.
Suppose, for example, that one desired to graph the effects on temperature after the addition of specific volumes of water. Using prompted DAQ, one would insert a temperature probe, record a temperature, and remove probe. After the addition of the desired amount of water, he or she would again record the temperature.
Normal data acquisition, on the other had, is a continuous retrieval of data.