What do students learn in school? In the 21 century, this question has become a political dilemma for countries around the globe. It is a deceptively simple question, but there has never been an easy answer. The problem of measuring student learning appears to express an educational problem: What and how much do students learn? Most student learning, especially the most important types of social learning and formative interactions, happens outside school, especially in early childhood. These personal experiences later go on to affect students' performance in schools. The most important variables that affect a student's school achievement are environmental. These three variables, which are deeply intertwined, are the social construction of: race, parental income and wealth, and parental education (especially the highest level of schooling that parents achieve). Most policymakers and school administrators talk as if schools and teachers have complete control over the student learning process, but most of the important variables that determine student success, especially in terms of learning and graduating, are beyond the control of teachers or schools. While it is certainly reasonable for teachers to use tests and grades to evaluate and measure student learning, these tools are not easy to implement in a valid way that promotes student learning and development.