Gram staining in Microbiology for second-year MBBS students: Comparative study of student scores in Objective Structured versus Traditional Practical Examination

This cross-sectional comparative study on Gram staining was conducted in a medical college in Maharashtra, Western India. Fourth semester MBBS students (n=90) with prior exposure to traditional practical examination in Microbiology were randomized by lottery method and divided into three groups of 30 students each. Students in Groups 1 & 3 were evaluated by traditional practical examination. Group-2 students rotated through a 3-station objective structured practical examination wherein the pre-validation of the checklist and questionnaire was done by university-approved senior teachers. There were significant differences in the marks scored by students in Groups 1 & 3 (Z=3.818; p<0.002) though they were exposed to the same pattern of traditional practical examination. This could be ascribed to inadequate uniformity in the allocation of marks. The standard deviation of scores for Group-2 (objective structured practical examination group) was the least among the three groups indicating consistency in allocation of marks.