Standard setting: A comparison of case-author and modified borderline-group methods in a small-scale OSCE

Purpose. To compare cut scores resulting from the case-author method and the modified borderline-group method (MBG) of standard setting in an undergraduate objective structured clinical examination (OSCE), and to review the feasibility of using the MBG method of standard setting in a small-scale OSCE. Method. Sixty-one fourth-year medical students underwent a ten-station OSCE examination. For the eight stations used in this study, cut scores were established using the case-author and MBG methods. Cut scores and pass rates were compared for individual stations and the entire exam. Results. The case-author and MBG methods of standard setting produced different cut scores for the entire examination (5.77 and 5.31, respectively) and for each station individually. The percentage of students failing the examination based on the case-author cut score was 42.2%, and based on the MBG cut score it was 15.25%. Conclusions. The case-author and MBG methods of standard setting produced different cut scores in an undergraduate OSCE. Overall, the MBG method was the more credible and defensible method of standard setting, and appeared well suited to a small-scale OSCE.