Strategies for Interpreting and Reporting Intervention Effects on Subgroups

November, 2010

This revised paper examines strategies for interpreting and reporting estimates of intervention effects for subgroups of a study sample. Specifically, the paper considers: why and how subgroup findings are important for applied research, the importance of prespecifying subgroups before analyses are conducted, and the importance of using existing theory and prior research to distinguish between subgroups for which study findings are confirmatory, as opposed to exploratory.

April, 2011
Pei Zhu, Robin Tepper Jacob, Howard Bloom, Zeyu Xu

This paper provides practical guidance for researchers who are designing and analyzing studies that randomize schools — which comprise three levels of clustering (students in classrooms in schools) — to measure intervention effects on student academic outcomes when information on the middle level (classrooms) is missing.

Elementary schools that educate children at risk of academic failure have traditionally responded by offering remedial instruction that slows the pace of learning. Research suggests, however, that remediation makes it harder for students to catch up and join the educational mainstream.