Psychometric properties of the California Critical Thinking Tests

The evaluation of critical thinking, as with any other measure, must employ instruments that meet appropriate psychometric standards. Therefore, the purpose of this study was to investigate the psychometric properties of the two California Critical Thinking Tests. Two samples of undergraduate students enrolled in a southern comprehensive university took the California Critical Thinking Skills Test (TST) and the California Critical Thinking Dispositions Inventory (TDI). A portion of the participants, who were nursing students, were retested on the TST and TDI two weeks after the initial testing. Some participants also completed the Watson-Glaser Critical Thinking Appraisal (WGCTA). In both samples the TST had neither sufficient psychometric properties to assess individual abilities nor sufficient stability reliability. In particular, the analysis subscale of the TST demonstrated exceptional weakness in all administrations. In contrast, the TDI demonstrated very good reliability estimates in all administrations of the test. The data did not conform to the subscale structure during factor analysis. Whereas the TST needs further refinement, the TDI demonstrated sufficient reliability for use in attitudinal research.