A comparison of the clinical performance of students in two grading systems: letter and pass-fail

The effects of letter and pass-fail grading systems on student performance have been little tested in the clinical setting. Thus, the present experiment was conducted to compare (1) the clinical performance of dental hygiene students in the two grading systems, and (2) student impressions regarding the effects of each grading system on performance. Performance was defined as the number of errors detected at the completion of three scaling/polishing procedures. Student impressions were assessed using a two-question, posttest questionnaire. Dental hygiene students (N = 19) in their first semester of patient care experiences were randomly assigned to letter and pass-fail groups. At the end of six months, the mean performances of the two groups were compared using the Student's t-test. Student impressions were compared using the Mann-Whitney test. No difference in clinical performance was detected between the two groups (p = .702), with a high level of performance demonstrated by both groups (about four total errors). Significant differences in student impressions were found, with the pass-fail subjects perceiving both types of grades as less important and less motivating to clinical performance than the letter subjects (p less than .05). These findings imply that a similar level of performance can occur with either grading system in the clinical setting. However, a pass-fail system may be more appropriate, since (1) it may motivate more task interest in clinical activities, and (2) the use of letter grades is more problematic. If further studies demonstrate similar results, dental hygiene educators should seriously consider implementation of pass-fail systems in the clinical setting.