All Direct Instruction programs are developed with extensive field testing. Most traditional programs are published without first undergoing extensive trials in real-world learning environments. In contrast, Direct Instruction programs are field-tested to determine the extent to which students actually master the material presented in a program and the extent to which teachers are able to adhere to the program’s presentation specifications.

Field testing begins as the Direct Instruction programs are being developed. The authors select several classrooms in which to field test the first version of the curriculum. These classrooms are selected to include a variety of students and teachers. At least some of these classes must include the lowest performing students who will be placed in the program. This is important because lower performers make all the mistakes higher performers make, plus additional mistakes higher performers tend not to make. 

Every activity in the field-test version of the program is assessed. Data are collected on the number of students who miss particular items and the incorrect responses they provide. Rules are established for when student performance indicates a need to revise the teaching sequence. Student errors are analyzed to determine how the instructional sequence likely contributed to the student’s problems. Revisions may include:

• making the initial explanations clearer
• including more thorough teaching of component skills that were not adequately taught
• providing for more scaffolding to prompt students to apply strategies
• providing more practice to help students discriminate when to apply strategies
• other elements that will improve the instruction

The revised version of the curriculum is then field-tested and revised again. Data are recorded for each student’s performance on each item. In addition to data on student performance, information on how long it takes to present tasks is collected, as well as feedback from teachers on the clarity of directions.

Each element of this field-testing procedure is essential to providing teachers with a program that is an effective instructional tool for all students. The extensive testing that underlies the development of Direct Instruction programs is the primary reason that they are so effective.