innovations are effective. That may be the case in the world of pure science. But the world of education is far less rigorously controlled or controllable. Though “scientifically based” research and randomized trials, commonly used in medicine, have garnered favor in Washington policy circles, in fact they are rare and somewhat controversial in education. And though the Department of Education “is committed to ‘evidence-based policy making,’” as the Science authors remind us, that commitment reasonably must suggest something short of the standard governing pure science. It is costly and logistically burdensome to design and monitor identical learning environments that isolate the specific approach being studied. Assigning students at random to unproven programs, moreover, is not only unpopular with parents, but it also raises ethical concerns. In the case of single-sex schooling, federal law prohibits the assignment of students to schools on the basis of while the 2006 Title IX regulations explicitly require that such programs remain voluntary. Quasi-experimental designs that use statistical techniques, including multi-level modeling, can control for quantifiable variables like parental education or income. Yet they cannot accommodate the many immeasurable factors that affect educational outcomes. Furthermore, as a recent comprehensive overview of findings indicates, individual studies differ in their methodology, analytical techniques, and outcomes measured. They also differ in the variables they isolate. Some control for student factors like prior ability. Others control for institutional factors like instructional hours. Most of the more scientifically rigorous studies on school effects are limited to one or two years due in large part to the financial costs in conducting such research and the fact that students drop off from the study each year. Economically disadvantaged students have an especially high degree of mobility. And though meta-analyses of existing studies provide some insight into programmatic success, they too are
in proportion to the number of males in the testing environment. The more males present, the lower the females’ math performance. In view of these differences, the researchers conclude that perhaps females benefit when placed in single-sex math classrooms. These findings, taken together, suggest that girls gain from learning environments where the message conveyed is that intelligence is not static but rather can be developed over time through experience and That takes us back to the single-sex findings from abroad. The third study examined students randomly assigned to single-sex and coeducational high schools in Seoul, South Korea. Random school assignment has been a matter of policy in both public and private schools in Seoul since 1974, thus mitigating the potentially skewed effects of both selection bias and the enthusiasm that comes with novel programs. The study found a significant correlation between attending an all-boys’ or an all-girls’ school and higher scores on Korean and English language tests. Graduates of single-sex schools also were more likely to attend a four-year college and less likely to attend a two-year college than graduates of coed schools. The researchers conclude that, even after accounting for school level variables such as teacher quality, student-teacher ratio, the proportion of students receiving free lunch, and whether the school was public or private, the positive effects of single-sex schooling were “substantial.” An additional study from Germany addressing the continued math gap favoring boys is also worthy of note. Even though students were not randomly assigned to separate or mixed groups, the findings nonetheless suggest that single-sex schooling may be a psycho-social variable influencing visual-spatial skills related to math achievement. In that case, researchers compared the performance of 250 students, in 8th and 12th grades, attending single-sex (84 girls) and coed (84 girls and boys each) Gymnasia (academic high schools) in solving a mental