Measuring Usable Knowledge: Teachers' Analyses of Mathematics Classroom Videos Predict Teaching Quality and Student Learning

This study explores the relationships between teacher knowledge, teaching practice, and student learning in mathematics. It extends previous work that developed and evaluated an innovative approach to assessing teacher knowledge based on teachers' analyses of classroom video clips. Teachers watched and commented on 13 fraction clips. These written analyses were coded using objective rubrics to yield a reliable and valid indicator of their usable teaching knowledge. Previous work showed this measure to correlate with another measure of teacher knowledge and to predict students' learning from the teachers' fraction instruction. In this study, the authors replicated those findings and further showed that the effect of teacher knowledge on student learning was mediated by instructional quality, measured using video observations of teachers' lessons.