The Early Childhood Environment Rating Scale-Third Edition (ECERS-3) is the latest version of one of the most widely used observational tools for assessing the quality of classrooms serving preschool-aged children. This study was the first assessment of its factor structure and validity, an important step given its widespread use. An ECERS-3…

Young children are able to benefit from early science teaching but many preschool teachers have not had opportunities to deepen their own understanding of science or to develop their pedagogical content knowledge (PCK) in relation to specific science topics and concepts. This study presents the results of efficacy research on Foundations of…

In this study, the relationship between differentiated instruction, as an element of data-based decision making, and student achievement was examined. Classroom observations (n = 144) were used to measure teachers' differentiated instruction practices and to predict the mathematical achievement of 2nd- and 5th-grade students (n = 953). The…

The purpose of this replication study was to examine the impact of the Teacher Study Group (TSG) professional development in vocabulary on first-grade teachers' knowledge of vocabulary instruction and observed teaching practice, and on students' vocabulary knowledge. Sixty-two schools from 16 districts in four states were randomly assigned to…

This article describes the development and validation of two forms of the Geometry Assessments for Secondary Teachers (GAST), which were designed to assess teachers' knowledge for teaching geometry. Both forms were developed by teams of mathematicians, mathematics educators, psychometricians, and secondary classroom geometry teachers. Predictive…