Scores derived from intelligence instruments predict many important outcomes in life, so it is not surprising that researchers and clinicians seek out interventions aimed at increasing these scores. Dixon et al. (J Behav Educ, 2019. https://doi.org/10.1007/s10864-019-09344-7) recently investigated the relation between instruction based on…

Understanding the effects of class size reduction (CSR) has been an enduring issue in education. For the past 3 decades, Project STAR has stimulated research and policy discussions regarding the effects of CSR on a variety of outcomes. Schanzenbach (2007) reviewed STAR studies and concluded that small classes improved student academic outcomes.…

U.S. social programs, set up to address important problems, often fall short by funding specific models/strategies ("interventions") that are not effective. When evaluated in scientifically-rigorous studies, social interventions in K-12 education, job training, crime prevention, and other areas are frequently found ineffective or…