Furedy and Biederman cited unreported silent parameters as the reason for their failure to replicate one of Badia and Culbertson’s (1972) experiments. Badia and Culbertson reported that rats prefer signaled electric shock to unsignaled. The purpose of the present experiment was to determine if the preference for signaled shock would emerge, using the Badia and Culbertson procedure, in a different laboratory and, hence, to evaluate the Furedy and Biederman speculation about silent parameters. Rats were shocked, in one of two conditions, at unpredictable times throughout each session. In the signaled conditions, each shock was preceded by a tone; in the unsignaled condition, no shock was preceded by a tone. Later, when given the opportunity, each rat changed the unsignaled condition to the signaled condition. The results are very similar to those of Badia and Culbertson. It was concluded that the changeover procedure is valid, reliable, and interpretable.