Two existing core-curriculum, non-science-majors-oriented classes (approximate total enrollment 400/year; 2 natural science, 1 social science) will be modified in the following ways: small discussion sections focused on "ill-structured problems" will be incorporated into existing laboratory periods, lecture styles will be modified to encourage more student involvement during class, and existing wet laboratories will be modified to include more computer assisted exercises. These changes are modeled after Perry's theories of "cognitive development." Faculty and student teaching assistants assigned to the course will receive prior training (a workshop led by Dr. Craig E. Nelson of Indiana University, a recognized authority in the field) in the methods to be used. Assessment of student pre and post course critical thinking skills and attitudes towards education and towards science and scientists will be by interviews of students and a paper and pencil test to be selected. An educational consultant interested in developing critical thinking skills will conduct the testing phase of the proposal and will advise concerning appropriate forums for dissemination.