Context: Professionalism development entails learning to make judgments in ambiguous situations. A Concordance of Judgment Learning Tool (CJLT), comprised of 20 vignettes involving professionalism issues, was developed. Students obtained a measure of how concordant their judgments were with a panel of experts and learned from given explanations. Method: Twenty clinical vignettes implying professionalism issues were written including, for each, four possible courses of action. Expert panel, nominated by all clerkship students, was made up of attending physicians that best represented professionalism role models. Experts completed CJLT and gave explanations for their answers. All clerks were invited to answer each vignette, and then received automated expert feedback including explanations. Results: Seventy-nine students sat for the activity. The optimized test included 20 cases and 54 questions (Cronbach's alpha coefficient of 0.64). Student – expert concordance scores ranged from 54 to 77 with a mean at 64.6 (standard deviation 5.1). Satisfaction survey results indicated high satisfaction and relevance of tool despite some pitfalls. Post-test focus group data revealed relevant experiential learning on professionalism issues. Discussion: Students' scores and perceptions suggest pedagogic relevance of the CJLT in fostering professionalism development in clerkship. CJLT is user-friendly and shows promise as a situation experiential learning activity. [ABSTRACT FROM PUBLISHER]