This article develops a new approach for calculating appropriate sample sizes for school-based randomized controlled trials (RCTs) with binary outcomes using logit models with and without baseline covariates. The theoretical analysis develops sample size formulas for clustered designs in which...

The article begins by giving an overview of spatial thinking concepts that are relevant to evaluation. The article relates the spatial perspective to both a realist evaluation and a randomized control trial perspective in evaluation to demonstrate the benefits of a spatialized program and...

This paper draws on data and experiences observing and analyzing school lotteries from the National Evaluation of Charter School Impacts (Gleason et al., 2010) to describe the challenges associated with lottery-based research. In that study, covering 36 charter middle schools in 15 states, we...

In Senegal mutual health organizations (MHOs) have been present in the greater region of Thiès for years. Despite their benefits, in some areas there remain low take-up rates. We offer an insurance literacy module, communicating the benefits from health microinsurance and the functioning of...

We have run experimental interventions to promote HIV tests in a large firm in South Africa. We combined HIV tests with existing medical check programs (MSP and HCT) to increase the uptake. We have implemented three interventions intended to reduce fears and stigma for HIV tests: opt out, risk...

This article draws on data and experiences observing and analyzing school lotteries from the National Evaluation of Charter School Impacts to describe challenges associated with lottery-based research. It presents evidence on the prevalence of oversubscribed charter middle schools and compares...

RCTs have become popular in the development community as part of the response to the results agenda. These studies are well placed to address the question of which programmes work or not. And, properly designed, they can be embedded in a broader evaluation design which also addresses questions...

This article draws on data and experiences observing and analyzing school lotteries from the National Evaluation of Charter School Impacts to describe challenges associated with lottery-based research. It presents evidence on the prevalence of oversubscribed charter middle schools and compares...