Few educational issues have received more attention in recent times than the problem of ensuring that our nation's elementary and secondary classrooms are all staffed with quality teachers. There is consensus that the quality of teachers and teaching matter--and undoubtedly are among the most important factors shaping the learning and growth of students. Moreover, there is consensus that serious problems exist with the quality of teachers and teaching in the United States. Beyond that, however, there appears to be little consensus and much disagreement--especially over what teacher quality entails and what the sources of, and solutions to, the problem might be. This issue of CPRE Policy Briefs summarizes the findings on issues related to teacher quality in the chapter authored by me in the book, The State of Education Policy Research (Cohen, Fuhrman, Mosher, Eds., 2007). This report also draws on discussions that took place during a summer, 2006, policy briefing on teacher labor-market issues held in Chicago and sponsored by the Spencer Foundation. In this brief, I will briefly discuss three related diagnoses and their attendant prescriptions: restrictive occupational entry barriers; teacher shortages; and underqualified/underprepared teachers. These diagnoses are not the only explanations for the problem of low quality of teachers and teaching. Nor are these views universally held--indeed, each is the subject of much contention--and proponents of one are at times opponents of another. But all are prominent views, all are part of the conventional wisdom as to what ails teaching, and all have had an impact on research, reform, and policy. The thesis of this brief, however, is that each viewpoint is largely misinformed or misconstrued. My theoretical perspective is drawn from the sociology of organizations, occupations and work. My operating premise, drawn from this perspective, is that to fully understand issues of teacher quality requires examining the character of the teaching occupation and the nature of the organizations in which teachers work. A close look at the best data available from this perspective, I argue, shows that each of these views involves a wrong diagnosis and a wrong prescription. In the following sections, I review each of the above views and explain why each conveys an inaccurate explanation of--and solutions to-- the problems of quality plaguing the teaching occupation.