As I coach teachers in classrooms on instructional practices that improve outcomes for struggling students, I have become convinced that formative assessment is one of the most powerful tools we have for ensuring student success. Formative assessment is a tool that provides teachers with critical information throughout a lesson that can be used to improve teaching practices and student achievement. In contrast to summative assessment, which tells us whether students have mastered or failed to master content and skills at the end of a course of study, formative assessment guides both students and teachers during instruction and helps them to avoid failure altogether (Bambrick-Santoyo, 2010). .
