When attempting to determine if an intervention has a causal impact, the "gold standard" of program evaluation is the randomized controlled trial (RCT). In education studies random assignment is rarely feasible at the student level, making RCTs harder to conduct. School-level assignment is more common but this often requires considerable resources…

This paper reviews both the content and the methodological issues involved in the small but growing number of empirical studies on the use of Direct Instruction programs and teaching procedures with special populations. The research reviewed includes experimental and quasi-experimental work, summative evaluations of entire programs, and…