One of the goals of higher education is to develop the students' ability to think critically. However, little research has been done to indicate the impact of college on students' critical thinking skills. A study conducted at a midwestern university measured the critical thinking capability of college seniors. Subjects, 37 volunteers derived from a previous study, had their critical thinking ability measured by an original essay question designed to force the students to indicate what cognitive processes they go through, and what questions they ask when engaged in critical evaluation. The analysis of their responses was divided into two scoring categories: specific criticisms and general criticisms. The results indicated (1) that 40% of the sample identified at least one appropriate general criticism and 17% identified more than one; (2) the students' specific criticisms showed a general failure to focus on definitional issues; (3) that many seniors lack fundamental critical thinking skills; and (4) that while most students were able to identify some flaws in statistical reasoning, they generally failed to recognize ambiguities, questionable assumptions, and value preferences--important components of critical evaluation. (MS)