Development of a new scoring system for accurate estimating learning outcome achievement by single best answer multiple-choice questions of preclinical students in medical microbiology course

• Main Authors: Yodying Dangprapai, Popchai Ngamskulrungroj, Sansanee Senawong, Patompong Ungprasert, Azian Harun
• Format: Article
• Language: English
• Published: American Society for Microbiology 2020-02-01
• Series: Journal of Microbiology & Biology Education
• Subjects: SBA-MCQ; assessment; medical microbiology; preclinical teaching; learning outcomes
• Online Access: http://jmbesubmissions.asm.org/index.php/jmbe/article/view/1773
• ISSN: 1935-7877; 1935-7885

Unlike in clinical years, when using a single best answer multiple-choice question (SBA-MCQ) to test higher-order cognitive processes in preclinical-year medical students, simultaneous assessment of two or more learning outcomes is often required. However, it can be difficult to pinpoint which learning outcome has been achieved. We invented here a new scoring system for SBA-MCQ to accurately estimate the learning outcome achievement based on a step-by-step SBA-MCQ and also investigated whether the traditional SBA-MCQs accurately estimated the learning outcome achievement of students. Enrolled into this study were third year medical students (n=316) taking a basic microbiology course at the Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand, in 2017. A step-by-step SBA-MCQ with a new scoring system was created and used to evaluate the efficacy of traditional SBA-MCQs for evaluating learning outcome achievement. The scores in percentages for these two methods were compared. The comparison was done in duplicates by using step-by-step/traditional SBA-MCQ1 and step-by-step /traditional SBA-MCQ2. The mean score obtained with traditional SBA-MCQs was significantly lower than that obtained with step-by-step SBA-MCQs (85.9% for traditional- versus 90.9% for step-by-step SBA-MCQ1, p < 0.001; 81.5% for traditional- versus 87.4% for step-by-step SBA-MCQ2, p < 0.001). Moreover, 65.8% and 87.8% of students scored lower in the traditional SBA-MCQ1 and the traditional SBA-MCQ2, respectively. These results suggest that traditional SBA-MCQs scores need to be interpreted with caution because they often underestimate knowledge and achievement of students. Therefore, the step-by-step SBA-MCQ is preferable method and should be used for examination in preclinical year.