Can simple instructions to use spaced practice improve ability to remember a fact? An experimental test using telephone numbers

As part of class demonstrations, college students were given single seven-digit telephone numbers and asked to memorize them according to one of two different sets of instructions. Control instructions asked the students to memorize the number as they “normally would.” Experimental instructions recommended a form of spaced practice. After 2 weeks, recall was tested and confidence ratings obtained. The spaced-practice instructions produced significantly better recall than did control instructions. Confidence in incorrect answers was slightly lower in the experimental than in the control group, indicating that recommending the study method did not engender false confidence. Thus, merely prescribing spaced practice can help people memorize more effectively.