This paper examines the ineffectiveness of evaluation instruments for evaluating teacher instructional performance and compares evaluation with clinical supervision. Supervision identifies what occurs within classrooms, emphasizing teachers' instructional performance, while evaluation also includes other areas such as the teacher's appearance, parent and peer relationships, attendance, promptness, and adherence to school policies. Research indicates that most teachers prefer supportive supervision, agree with the principles of clinical supervision, and prefer it. Clinical supervision is an ongoing, formative process that emphasizes the relationship between classroom performance and the teacher's espoused goals. It includes four basic steps: the pre-observation conference, the observation, analysis and strategy development, and the post-observation conference. Formative clinical supervision emphasizes coaching and feedback; collegiality is the key to its success. The results of an evaluation mandated by state level offices can be very ineffective, with the mandated evaluation tools undermining high quality education. Evaluation and supervision processes can complement and support each other when carried out in a supportive and collegial way. (Contains 19 references.) (SM)