K-12 Single-Sex Education: What Does the Research Say? (continued)

Attitudes Toward Academic Subjects 

Several studies found that girls in single-sex schools may have stronger preferences for subjects such as math and physics than their coeducated peers. Mallam (1993) found that students in all-girls' Nigerian schools favored math more than girls in coed Nigerian public boarding schools, particularly when mathematics was taught by female teachers. Finally, Colley et al. (1994) surveyed British students (ages 11-12 and 15-16 years) from single-sex girls' and boys' schools and coeducational schools, asking them to rank their school subject preferences. In the younger age group, girls from single-sex schools showed stronger preferences than their coed peers for stereotypical "masculine" subjects such as mathematics and science, and boys from single-sex schools showed stronger preferences for stereotypical "feminine" subjects such as music and art. 

Achievement Variables

Research findings are ambiguous concerning the effects of single-sex schools on girls' achievement. For many studies that did find gaps favoring girls in single-sex schools, once findings were adjusted for socioeconomic or ability variables, these differences diminished. For example, Harker and Nash (1997) used data gathered in a longitudinal study of more than 5,000 eighth- grade students in New Zealand and controlled for individual characteristics (such as socioeconomic status) and school type. As with other studies, the researchers confirmed statistically significant differences in favor of girls at single-sex schools. Yet after applying controls for ability levels and for social and ethnic backgrounds, differences disappeared. LePore and Warren (1997), using data from the National Educational Longitudinal Study of 1988, found that boys in single-sex schools did not increase their test scores more than boys in coeducational schools and that girls experienced no statistically significant positive effects of single-sex school enrollment. 

Studies that have found positive achievement outcomes attributable to the single-sex environment have all dealt with single-sex schools rather than classes. A study by Riordan (1990) used longitudinal data to clarify the effects of single-sex education on different populations and curricular areas. Riordan conducted separate analyses for students by sex and race on academic and attitudinal outcomes. He discovered that among African American and Hispanic American students attending Catholic secondary schools, both males and females in single-sex schools scored higher on standardized cognitive tests than their peers in mixed-sex schools. To explain the differences, Riordan applied a set of school variables as controls. He argued that policies in single-sex schools that emphasize the academic side of these variables explained virtually all of the test score differences between the two types of schools. Both males and females in single-sex schools also gained on attitudinal variables such as leadership behavior, but much less of this difference was explained by school variables.