In this study, numerical course scores of second-year dental students in four successive classes in an oral and maxillofacial pathology course were compared. While the course content and teaching methods were essentially unchanged throughout the four years, two modest departures from the sole use of multiple-choice format questions were made in the assessment of student achievements. The modifications consisted of creating a more challenging examination procedure through the inclusion of un-cued short-answer format questions and the institution of correction-for-guessing scoring on multiple-choice examinations. Academically, the students in the four classes were comparable, as indicated by their respective numerical course score distributions in a prerequisite general pathology course in which the course content was unchanged, and all multiple-choice format questions were used to assess student academic achievements. This four-year study demonstrated that two qualitative changes in the educational environment-utilization of un-cued short-answer questions and correction for guessing scoring of multiple-choice questions-separately resulted in significant improvements in student course scores. Our results support the notion that, without any changes in curricular content or emphasis, combinations of qualitative changes in the assessment procedures alter student behavior and, as a consequence, appreciably improve their academic achievements.