The Mathematica study of charter middle schools, just released by the U. S. Department of Education, finds no achievement gains within two years for students who won the charter lottery as compared to those who did not. Ordinarily one would take such a study seriously, because it compares similar groups of students who differ only in the luck of the draw. But the study was set up in such a way that it could not possibly tell us much about charter schools.Mathematica, the firm that did the study, chose to study only those students who entered a charter middle school after having first taken a standardized test in a public school. Since standardized tests typically are not given before third grade, charter students included in the study consisted mainly of students who moved from traditional public school to a charter school in fourth grade or later. We know from other studies that students typically lose ground when they change schools. Data from the State of Florida indicates that achievement gains by students who move from one public school to another badly trail the gains of students who remain in the same school—even after one has adjusted for many family background characteristics.Along these same lines, the Mathematica study shows that students who change to charter schools do not perform better than those who did not change schools. The study, however, reveals nothing about the experience of attending a charter school from the very beginning—nor about the longer term impact of attending a charter school.Source: EducationNext