Two forms of assessment, summative and formative, are the primary means by which teachers determine student progress and achievement. Summative assessments help teachers determine what students have learned at the end of a unit of instruction. They are often used to help teachers determine whether their instruction was effective or to grade students. Unlike summative assessments, formative assessments are primarily used to inform teachers about what students know before a unit of instruction or what they are learning as a unit progresses. They are critical for informing teachers and students of their progress toward achieving the national standards, and they need to be an integral component of the instructional process in today's schools. This article informs teachers about formative assessment and provides examples of how K-12 teachers can integrate PE Metrics into instruction in order to determine progress toward student learning.