Although randomized studies have high internal validity, generalizability of the estimated causal effect from randomized clinical trials to real-world clinical or educational practice may be limited. We consider the implication of randomized assignment to treatment, as compared with choice of preferred treatment as it occurs in real-world…

Selection bias is problematic when evaluating the effects of postsecondary interventions on college students, and can lead to biased estimates of program effects. While instrumental variables can be used to account for endogeneity due to self-selection, current practice requires that all five assumptions of instrumental variables be met in order…

This study examined the average effects of schools' third through fifth grade gifted programming policy in mathematics and reading on overall school achievement, on gifted students' achievement and academic attitudes and on nongifted students' achievement and academic attitudes. Data and results represent a broad, national look at school…

We study a set of programs implemented in Philadelphia high schools that focus on boosting high school graduation, and especially college attendance, using data from the Philadelphia Educational Longitudinal Study (PELS). We examine the effects of these programs on a set of schooling-related outcomes during and after high school. The PELS data-set…

Using college transcripts, we separate the effects of remedial coursework from high school preparation. For two-year colleges, taking remedial classes was "not" associated with less academic success. In four-year colleges, there "are" negative effects of remedial coursework, but many minority students who complete a bachelor's…