Do single-sex classes affect academic achievement? An experiment in a coeducational university
通过随机分配学生到单性别或男女混合班级的实地实验，研究单性别教育对学业成绩的影响，尤其关注女性学生的心理机制。
However, despite the criticisms of single-sex education, there are a number of potential psychological reasons for expecting a positive effect for young women in single-sex classes.For example, females in all-female classes may feel more confident and gain higher levels of self-efficacy (Gist and Mitchell, 1992); they may experience a reduction in stereotype threat (as discussed in Spencer et al., 1999; Steele, 1997; or Steele et al., 2002) or a reduction in psychological threat (as discussed in Cohen et al., 2006).Recently, there have been some important new studies aiming to estimate the effect of single-sex education on various educational and economic outcomes.These typically rely on comparing students attending different types of primary or secondary schools, or, within a school, comparing students who already knew they were likely or unlikely to attend singlesex classes.For instance, Park et al. ( 2012) compared students in co-ed high schools that are primarily publicly funded with students in gendersegregated schools that are primarily privately funded.Eisenkopf et al. (2015) examined students who chose to attend a school where 85 per cent of the population was female, meaning it is very likely that many students would be in single-sex classes.Booth and Nolen (2012a, 2012b) looked at publicly funded selective single-sex schools that they compared with the academic stream of publicly funded co-educational schools.In these studies, the ex ante choice of a primarily female school may bias the results, as argued by Jackson (2012), who shows that females who benefit from single-sex education are those with a preference to attend single-sex schools.It was for this reason that we chose in the present study to assign students randomly to single-sex and co-ed classes in a field experiment, and to follow them over time.