A large body of studies exists that examines the relationship between student achievement gains and the characteristics of teachers. To help policymakers and researchers use and build on this body of studies, this article reviews the studies systematically and synthesizes their results with deliberate consideration of each study’s qualities. Determinate relationships are described for four categories of teacher characteristics: college ratings, test scores, degrees and coursework, and certification status. The review details the implications of these relationships in light of study limitations and proposes directions for future research.

A strong base of research is needed to guide investments in teacher professional development (PD). This article considers the status of research on PD and articulates a particular direction for future work. Little is known about whether PD can have a positive impact on achievement when a program is delivered across a range of typical settings and when its delivery depends on multiple trainers. Despite a consensus in the literature on the features of effective PD, there is limited evidence on the specific features that make a difference for achievement. This article explains the benefits offered by experiments in addressing current research needs and-for those conducting and interpreting such studies-discusses the unique methodological issues encountered when experimental methods are applied to the study of PD.

An investigation of primary research studies on public school teacher supply and demand revealed four surprises. Projections show that enrollments are leveling off. Relatedly, annual hiring increases should be only about two or three percent over the next few years. Results from studies of teacher attrition also yield unexpected results. Excluding retirements, only about one in 20 teachers leaves each year, and the novice teachers who quit mainly cite personal and family reasons, not job dissatisfaction. Each of these findings broadens policy makers' options for teacher supply.With teacher quality atop local, state, and federal agendas, the body of policy research that addresses teacher quality is very much in the spotlight. Hopefully some of the knowledge generated by researchers can prove helpful to policy makers.But to a surprising extent, the research community is not offering policy makers much that they can use. The policy researchers who shape public understanding of the 2 of 8 teacher quality issue are now making considerable efforts to challenge each other's work (e.g., Podgursky, 1999, 2000;Darling-Hammond, 1999). Although that debate will have salutary effects over the long-term, the short-term outlook for lay audiences is confusion over whom to trust.This article attempts to make progress by focusing on questions whose answers depend on more broadly understood analytic tools. It focuses on teacher supply and demand-only one part of the teacher quality story. But knowledge about supply and demand can help policy makers, and the requisite analytic tools are so simple that disagreement is unlikely.My examination of the knowledge base on the supply and demand of public school teachers led to several surprises. Rather than summarize all that is known, what follows focuses on those points where the common wisdom is wrong. Each of the four sections below contrasts what primary research studies say with what policy makers hear about supply and demand.The original studies come from long-term federal investments in survey research, overseen by the National Center for Education Statistics (NCES). The NCES is regarded as the most authoritative source of national evidence on teacher supply and demand. Its survey methods and analyses are thoroughly documented, and all of its documents are publicly available at www.nces.ed.gov. Enrollments are Leveling OffClose examination of NCES projections reveals that enrollments are leveling off. Mischaracterizations of these projections are very common. A recent RAND publication referred to "a dramatic increase in enrollments" over the next decade (Kirby, Naftel, and Berends, 1999, p.

No abstract