Abstract

Most existing measures of critical thinking employ a structured response format that tends to elicit a restricted range of reasoning. The principal limitation of this approach is underrepresentation of the construct because the productive dimension of critical thinking is not measured. To address this problem, a new assessment instrument was developed to measure critical thinking ability using a constructed response format. ;Critical thinking was defined as the mental process of evaluating products of thought based on the judgment of evidence and assessment of reasons; it further includes the productive process of developing a logical argument. The instrument, the Wasatch Test of Critical Thinking, consists of three items: two editorials that the respondent analyzes and an essay question. In this study, the instrument was field tested on approximately 100 under-graduate students at a state university. Construct validity of the instrument was evaluated by investigating its substantive and structural components, its external relationship to another test of the construct, and the related construct of verbal ability as measured by vocabulary. ;A G-study generalizability analysis was used to estimate dependability and to determine the relative magnitude of the sources of variance. For a relative decision, the generalizability coefficient was.55. A second type of reliability was also calculated, interrater reliability, for which an estimate of.74 was obtained. ;The constructed response test of critical thinking was only marginally correlated with a multiple-choice test of critical thinking. Also a low correlation of.37 was obtained between the instrument and a vocabulary test. There was a moderately strong correlation between the critical thinking score and the length of response. The relationship between scores on the single essay item and scores for writing quality was examined. ;A significant effect on the critical thinking scores was found for academic class, academic major, and gender. Mean scores increased with each additional year of college education, and social science majors scored higher than students from most other disciplines. Women obtained significantly higher critical thinking scores; however, this may have been due in part to academic differences between the male and female examinees