The Iowa Test of Educational Development (ITED), a test of general abilities given to high school students, is intended as a tool for teachers and administrators to measure the progress of their students and plan accordingly; it also purports to assess the use by students of critical and evaluative abilities. Because such tests as the ITED carry significant weight in the educational system and in society at large, and because critical thinking skills have come to be recognized as one of the most important goals for education, it seemed appropriate in this report to investigate the validity of claims of the ITED to assess critical thinking ability. The overall structure of the ITED, the subtests, and procedures are analyzed and it is concluded that while the ITED is definitely better than most other tests in the area of critical thinking, it simply falls short of a comprehensive, balanced critical thinking assessment. An appendix presents, item by item, the critical thinking abilities found in the ITED. An 11-item list of references also is included. (DB)