Abstract
<p>Professional development (PD) is a key strategy for improving teacher effectiveness and student outcomes. This review examines trends in PD research over the past four decades, focusing on alignment with Hill et al.’s (2013) five-stage research framework and Desimone’s (2009) high-quality PD components. We included 107 experimental and quasi-experimental studies published between 1986 and 2022 that evaluated teacher outcomes following PD. Despite increased attention to PD, most research remains in early stages and lacks integration of established high-quality components. Greater investment in later-stage, large-scale studies is needed to understand the impact of PD on student outcomes and to guide future policy and practice.</p>