Critical thinking: change during medical school and relationship to performance in clinical clerkships.

The development of critical thinking, the ability to solve problems by assessing evidence using valid inferences, abstractions, and generalizations, is one of the global goals advocated by most medical schools. This study determined changes in critical thinking skills between entry and near the end of the third year of medical school, assessed the predictive ability of a test of critical thinking skills, and assessed the concurrent validity of clerkship components and final grade. The Watson-Glaser Critical Thinking Assessment (WGCTA) was administered to one class of students at entry to medical school and near the end of year 3. Performance data for those students who completed their clinical clerkships on schedule were also recorded. Critical thinking improved modestly but significantly from entry to medical school to near the end of year 3. The ability of a critical thinking test to predict clerkship performance was limited; the correlation between WGCTA total score at entry and the components and final grade of five major clerkships ranged from near 0 to 0.34. The concurrent validity of clerkship components and final grade was also limited; correlations with WGCTA total score near the end of year 3 ranged between 0.08 and 0.49. The correlation between WGCTA total score and United States Medical Licensing Examination Step 2 was higher at year 3 than at medical school entry. Critical thinking skills improve moderately during medical school. Used alone, tests of critical thinking may be of limited value in predicting which students will be successful in clinical clerkships. Clerkship evaluation components and final grade have limited concurrent validity when a test of critical thinking is the criterion.