Schilling et al. (this issue) have done a commendable job in illustrating a comprehensive process of validating assessments of teacher knowledge (and, more broadly, other types of tests as well). On one hand, the concrete illustration of a process that often remains murky and incomplete is profoundly heartening, as it provides a rigorous model for…

The idea that validity should be considered a property of inferences, rather than of assessments, has developed slowly over the past century. In early writings about the validity of educational assessments, validity was defined as a property of an assessment. The most common definition was that an assessment was valid to the extent that it…

Teacher knowledge has been of theoretical and empirical interest for over two decades, and development of measures is overdue. The researchers represented in this volume have been breaking new ground by developing a measure of mathematical knowledge for teaching (MKT) without guiding precedents, and in the face of differing perspectives on teacher…

Operating from multiple literature bases in cognitive psychology, mathematics education, and theoretical and applied psychometrics, Schilling, Hill and their colleagues provide a systemic approach to studying the validity of scores of mathematical knowledge for teaching. This system encompasses an array of task formats and methodologies. The…