This paper, one of the nine-booklet Teacher Quality Series, examines ten popular assumptions that underlie many new proposals to solve the problems of the teacher workforce. It is argued that many of these assumptions are unsupported by research on teaching. It is also suggested that the ability to attract, train and keep good teachers depends heavily on base salary, the organizational conditions of work, and the professional development opportunities in addition to the type of incentive system offered by the school. The following unsubstantiated assumptions (or "myths") are discussed: (1) pay teachers and they will teach better; (2) competition among teachers for career advancement and higher pay is a sound way to improve the quality of their service; (3) promotions and incentive pay will keep good teachers in teaching; (4) career ladders will encourage teachers to improve; (5) career ladders and incentive pay will attract more academically talented people into teaching; (6) teachers who are promoted up career ladders can evaluate other teachers for promotion; (7) since almost everyone can recall at least one great teacher, the characteristics of great teachers are easy to identify; (8) the scores students make on tests are a good measure of teacher effectiveness; (9) an effective teacher is equally effective in all settings; and (10) good teachers are born not made. A four-page reference list and a page of information concerning the Teacher Quality Series concludes the booklet. (JD)