Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
With the matched pair school randomized design of 30 schools, 90 tutoring groups, and an average of 20 students per group, the MDES for the main effects of either Remedial Support Mindfulness or Brain Games is 0.19.
School-level R-squared and intra-class correlation (ICC) estimates for these power calculations are based on estimates of 15 sub-Saharan African countries provided in Kelcey et al. (in prep). In this review, school-level ICCs ranged from 0.20 - 0.50; however, given the level of migration and integration in Diffa, we estimate clustering between schools to be in the lower range, around 0.20. In Kelcey et al., school-level R-squared estimates of socioeconomic status and school location ranged from 0.02 - 0.59. Given that we will have baseline school literacy and math scores (one of the strongest predictors of endline literacy and math scores), we anticipate a school-level R-squared between 0.50 and 0.70. Finally, effect sizes in evaluations of mindfulness and executive functioning programs in the US range from 0.25 - 0.80 (for executive functioning skills); and effect sizes in our evaluation of LIHC in the DRC ranged from 0.14 - 0.32 (for academic skills and perceptions of the school environment.).