Several systematic literature reviews have documented the efficacy of Direct Instruction programs:
Kinder and associates (2005) summarized the results of 37 studies that used Direct Instruction materials with students with disabilities. Over 90 percent of these studies found positive effects for the Direct Instruction programs.
Przychodzin and colleagues (2004) reviewed the results of 12 studies of DI math programs published since 1990. Some studies involved general education students and some also included students with disabilities. All but one of the studies showed positive results.
Przychodzin-Havis and colleagues (2005) reviewed 28 published studies of the Direct Instruction Corrective Reading program. Over 90 percent of the studies found positive results and only one study found greater gains with another intervention. Similar results appeared with different types of assessments (e.g. standardized tests or curriculum-based measures), in different settings, with different types of instructors (e.g. certified teachers, peers, aides), and with different research designs.
Schieffer and colleagues (2002) reviewed 21 studies of Reading Mastery that compared its use to that of another program. Results in fourteen of these studies (67%) favored RM, other programs were favored in three (14%), and there were no differences in the remainder.
Simonsen and Gunter (2001) looked at 18 studies of spelling programs and found that DI spelling programs consistently demonstrated better outcomes than comparison strategies. Positive results appeared for students in general education, elementary and middle school, and for students experiencing difficulties in the area of spelling.