Recruiting Participants for Large-Scale Random Assignment Experiments in School Settings

Abstract

Recruitment is a key challenge for researchers conducting any large school-based study, especially random assignment studies where researchers require certain level of control over experimental conditions and intervention implementation. Such studies often need to have a sample of 30-60 teachers or schools to have sufficient power to detect medium-sized effects of interventions. We report here on our experiences in recruiting participants for random assignment experiments in public primary and secondary schools. Our perspective is based on over twenty current and completed randomized controlled trials (RCT) in K–12 school settings conducted by SRI International, including studies of educational technology, literacy, mathematics, science, instructional materials, teacher professional development, and student behavioral supports, following What Works Clearinghouse standards for RCTs. Considering our experience across these studies, we reflect on how we approached the recruitment problem and what worked during our efforts. Our comments are organized in six topics corresponding to the aspects of an overall recruitment process: 1) Study design; 2) Intervention packaging; 3) Planning a recruitment process; 4) Designing recruitment messages; 5) Running a recruitment campaign; 6) After recruitment.