Scientific developments are based on carefully developed theory and rigorous empirical tests. The Direct Instruction approach to teaching exemplifies this tradition, with a strong theoretical base, the continual incorporation of research in program development, and hundreds of replications of research results. These results demonstrate the programs’ strong efficacy in varied settings and with different populations.
The theoretical propositions that underlie Direct Instruction are summarized and tested in books such as Conceptual Learning (1969), Theory of Instruction: Principles and Applications (1982), Inferred Functions of Performance and Learning (2004), and Could John Stuart Mill Have Saved Our Schools? (2004).These writings delineate the logical basis for DI’s basic principles that:
1) all children can learn when instruction is systematic, explicit, and efficient; and
2) poor achievement does not result from poor students, but from poor teaching.
They present the suppositions in formal logical terms, provide empirical tests of the theoretical propositions, and link the analyses to classic philosophical writings.
The development of DI programs is based on these theoretical principles and incorporates carefully designed research at all stages. DI authors pay particular attention to ensuring that the instructional programs are logical, explicit, and systematic, so they try out each element of a program to make sure it works. When students do not understand something, the authors assume that there is a problem in the program. They identify the problem, alter the instructional design, and then test it again. Once the instructional programs are fully drafted they are field tested in schools around the country. The sites are carefully selected to represent varied demographic and geographical settings. Feedback from these sites is used to again revise the programs as needed. No other instructional programs use such careful research procedures, or such a fully developed theoretical base, in their construction and design.
Once programs are published and widely disseminated, scholars from around the world examine their efficacy. Over the last five decades hundreds of studies of the efficacy of Direct Instruction have been conducted. These studies have involved all aspects of the DI curriculum, such as reading, math, language and spelling. They have included students in rural, suburban, and urban settings; students from preschool to adulthood; students with all types of demographic characteristics and ability levels; and students in the United States and in other countries. The studies have used a wide range of designs such as randomized control trials, large scale multi-site implementations, longitudinal studies, and single subject designs. This research has consistently found strong evidence that students exposed to Direct Instruction have higher achievement than those using other programs.
Extensive literature reviews and meta-analyses summarize this literature. Bibliographic citations of much of this literature are included in NIFDI’s Comprehensive Bibliography of the DI literature. Substantial proportions of this research are also included in NIFDI’s searchable database of DI related writings, and new research continues to appear.