A total of 53 high-ability students who had completed the eleventh year in high school enrolled in a standard college chemistry course at the University of Iowa. Half of them had completed a high-school course in chemistry and half had not. After 2 months of instruction during a summer session, there was no difference between groups as to attitude toward chemistry, performance on the ACS-NSTA Chemistry Achievement Examination, final examination for the course, and course grade. There was a great difference in the amount of time required of tutors; the students who had not completed high-school chemistry spent more time in studying and with tutors.