An extensive literature exists on what makes good teachers, focusing on their characteristics, their behaviors in the classroom, and the effects they have on their students. This literature points to three groups as being currently involved in defining good teachers: students, who, as research demonstrates, are reliable observers, fair and unbiased raters, and capable of describing the characteristics and behaviors of good teachers; external judges assessing student outcomes as the measure of educational effectiveness; and educational researchers, who through their counting, observing, experimenting, and surveying, attempt to provide generalizable definitions and criteria for teaching effectiveness. The literature on criteria for evaluating the quality of instruction is deficient in several areas, lacking good discussion of what teachers are trying to accomplish, a constructive approach to applying research to the improvement of practice, and a body of information on how to conduct research in the classroom. The most useful approach to filling these gaps in the literature, while at the same time improving undergraduate instruction, involves teachers doing research in their own classrooms and learning laboratories as a means of evaluating their effectiveness as teachers while fostering intellectual stimulation and professional renewal. Examples of the kinds of classroom research projects that might be undertaken include an investigation of the dropout problem, whether review sessions before exams promote long-term retention, or whether particular teaching methods are effective. While these kinds of projects do not generally call for complicated research methodologies, they should use acceptable standards of research practice if they are to have value in improving classroom teaching. (LAL)