This study investigated the reliability and validity of the Watson-Glaser Critical Thinking Appraisal-Form S for subjects in academic fields. The participants were 586 university students. The responses to the WGCTA-FS were analyzed for the total group and the subgroups within the total group: psychology majors, students enrolled in educational psychology and in special education, undergraduates, and graduate students. Data showed that the WGCTA-FS was a reliable and valid instrument measuring critical thinking for these groups of subjects.
Over the years, researchers, psychologists and educators have emphasized the importance of teaching and testing critical thinking skills (Ennis, 1987; College Board, 1983; and Task Force on Education and Economic Growth of the Education Commission, 1983). Siegel (1980) noted that educational philosophers viewed critical thinking to be the central idea in educational endeavors. Halpren (1988) stated that many educators viewed the promotion of critical thinking as one of the highest priorities in college education. Lawson (1999) felt that critical thinking should be part of the psychology students' overall assessment. Is there a valid and reliable instrument that can measure critical thinking in academic settings?
The Watson-Glaser Critical Thinking Appraisal Forms A and B (Watson & Glaser, 1980) were inventories frequently used in measuring critical thinking at the post-secondary level. Both of these instruments were too long. Most participants who had responded to these inventories did not complete them. In 1994, Watson and Glaser revised the Watson-Glaser Critical Thinking Appraisal Form A to a new version called Form S (WGCTA-FS). The WGCTA-FS has 40 items, thus, it is a much shorter inventory than the original WGCTA-Form A. A number of researchers, reported in the WGCTA-FS manual (Watson & Glaser, 1994b), have used this WGCTA-Form S with subjects who were primarily career applicants and business personnel. The purpose of the present study was to determine if the WGCTA-FS is a reliable and valid instrument measuring critical thinking for subjects in the academic fields.
Subjects: The participants were 586 students enrolled in courses at a southwestern state university, of which 56 were majoring in psychology, 228 enrolled in educational psychology, 155 enrolled in special education, 79 enrolled in graduate studies, and 68 did not as yet declare a major. The total number of undergraduates was 486.
Instrument: The data used in this study were the students' responses to the WGCTA-FS and their end of semester course grades. The WGCTA-FS has five scenarios to which subjects respond to questions about the contents in these scenarios. Five subscale scores are derived from these responses. The subscales are entitled as follows: (a) Inference: in which the subject determines to what extent one can discriminate the truth or falsity of the statement from the data provided; (b) Recognition of Assumptions: in which the subject recognizes whether the assumptions are clearly stated; (c) Deduction: in which the subject decides whether certain conclusions necessarily follow the information provided; (d) Interpretation: in which the subject considers the evidence provided and determines whether generalizations on the data are warranted; and (e) Evaluation of Arguments: in which the subject distinguishes between the strong and relevant arguments from those that are weak and irrelevant in particular issues (Watson & Glaser, 1994b). The Total Critical Thinking Appraisal score is a summation of the five subscale scores. It provides a more accurate estimate (than do each of the subscale scores) of individuals' overall proficiency with respect to attitudes, knowledge, and skills.
The internal consistency and test-retest reliability for the WGCTA-FS, reported in the WGCTA-FS manual (Watson & Glaser, 1994b), were both . …