Determination of the power to decide in uncertainty with the method of Script Concordance Test

Real-life professional problems may require making decisions, although the available information is limited or ambiguous. Incorporating such authentic uncertainties into an assessment, however, poses problems in analysing results and establishing its psychometric qualities. Based on the Script Concordance Test format, we developed a test on clinical decision making in veterinary medicine, incorporating realistic uncertainties. This test was administered twice to 148 students, near the beginning and the end of a course in clinical reasoning. Their answers were compared to the judgements and decisions of 28 experienced practitioners. Student scores on the pre- and post-test show a mean improvement of 4.59 points. Individual scores correlate positively (r = 0.65) and the effect size is large (d = 0.89). From the analysis and substantive appraisal of the cases and items, it is concluded that this SCT can be used for large student groups to assess competence in clinical decision making, without creating a burden on patients.