This paper outlines a development course on teaching critical thinking skills designed for both elementary and secondary teachers and supervisors. Improving a student's ability to use higher order intellectual skills has been recognized by national and state commissions as important in improving student achievement. To successfully improve the teaching of critical thinking skills, staff development plans must first review the thinking processes/strategies needed to accomplish the specific cognitive tasks of the subject disciplines. Bloom and his colleagues' (1956) theory of critical thinking, synonymous with the term "evaluation," is one conceptualization of higher order skills and is illustrated by an example of classroom instruction drawn from secondary English teaching. The second step in staff development is finding strategies for teaching critical thinking skills to students. Examples of teaching methods requiring that students develop and use critical thinking are presented. It is suggested that this staff development take place under the leadership of supervisory personnel or fellow teachers in a cooperative workshop.(CB)