From the halls of Congress to the local elementary school, conversations on education reform have tossed around the term "achievement gap" as though people all know precisely what that means. As it's commonly used, "achievement gap" refers to the differences in scores on state or national achievement tests between various student demographic groups. And the gap that has been a long-standing source of the greatest concern is that between white students and minority students, although other groups have been brought into the picture by No Child Left Behind (NCLB). The adequate yearly progress (AYP) requirements of NCLB are designed to expose achievement gaps between groups of students, ostensibly so that schools will make greater efforts to close the gaps over time. But making AYP is not the same thing as closing achievement gaps. The great hope--still far from being realized--is that, as achievement improves across all student subgroups, the gaps will diminish as well. It is important to remember that, despite being the major preoccupation of most educators and policy makers, making AYP is not an end in itself; rather, tracking AYP is a means to the dual ends of closing achievement gaps and improving the performance of all students.