A growing body of evidence confirms what common sense has suggested all along: The quality of teaching in the public schools matters for how well students learn. An important corollary is that poor children, minority children, and children from nonEnglish-speaking homes are even more dependent on the quality of their teachers than are more affluent, English-speaking, White children. Pressures to improve teacher quality stem mainly from state efforts to hold local schools accountable for student achievement and from the requirements of the No Child Left Behind Act. Policymakers want to know how to train, license, recruit, select, deploy, assign, develop, evaluate, retain, and compensate teachers to produce a well-qualified teacher in every classroom and especially in the classrooms that need them the most--those in urban, high-poverty, high-minority, low-performing schools (Ferguson, 1991; Sanders & Rivers, 1996; Sanders & Horn, 1998; Darling-Hammond, 2000). State policy counts as a salient force in shaping teacher quality, with influence in domains including teacher-licensing standards, teacher-education policies, compensation and evaluation, induction, professional development, and data policy and systems. These were key issues addressed by the National Commission on Teaching and America's Future (NCTAF, 1997) and the Teaching Commission (2004). This issue of CPRE Policy Briefs summarizes the findings on issues related to teacher quality in the chapter authored by Thomas B. Corcoran in the book, The State of Education Policy Research (Cohen, Fuhrman, & Mosher, Eds., in press). 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.