THIS STUDY REPLICATES EARLIER DATA CONCERNING CONDITIONS UNDER WHICH STUDENTS CHECK OR "OBSERVE" ANSWERS TO A PRINTED PROGRAM, AND THE RELATION OF ANSWER OBSERVING TO ERROR RATE. THIRTY COLLEGE STUDENTS STUDIED TWO PROGRAMS ON MEDICINE. FREQUENCY OF ANSWER OBSERVING WAS OBTAINED BY SELF-REPORT. PAY INCENTIVES (THE INDEPENDENT VARIABLE) WERE GIVEN TO ONE EXPERIMENTAL GROUP IMMEDIATELY BEFORE BEGINNING THE SECOND PROGRAM, AND TO ANOTHER IMMEDIATELY AFTER COMPLETION OF THE SECOND PROGRAM BUT BEFORE A POST TEST. IT WAS FOUND THAT THE PROBABILITY OF ANSWER OBSERVING ON ITEMS ANSWERED INCORRECTLY WAS HIGHER THAN ON FRAMES ANSWERED CORRECTLY BY AN INDIVIDUAL SUBJECT. INCENTIVES HAD AN INCONCLUSIVE EFFECT ON POST TEST SCORES. THIS PAPER APPEARED IN "STUDIES IN LANGUAGE AND LANGUAGE BEHAVIOR," PROGRESS REPORT V, SEPTEMBER 1, 1967. (LH)