Redefining the federal government's role in kindergarten through grade 12 education, the No Child Left Behind Act of 2001 is designed to close the achievement gap between disadvantaged and minority students and their peers. The act is based on four principles, the first of which is stronger accountability for results, entailing creation of standards against which student progress and achievement will be measured by annual state tests. This booklet explains the roles of these new state tests in improving student achievement and addresses some of the misunderstandings about the changes to come. Following an introduction, the first part of the booklet provides a rationale for measuring student progress, noting that each state retains the responsibility for deciding what their students should learn in each grade as well as devising assessments aligned to curriculum. The second part of the booklet explores myths and realities about testing, noting that testing is intended to establish benchmarks rather than narrow the curriculum, and that a well-designed evaluation system accommodates special needs. (HTH)