Mastery is at the core of all Direct Instruction (DI) programs. Each DI program is constructed using a small-step design that ensures that all students can be taught to mastery every day if they are placed properly in the program. Only 10-15% of a DI lesson contains new material. The rest of the lesson reviews or applies material taught in previous lessons so students can master the material and perform correctly on every task or exercise by the end of a lesson.
Appropriate placement is critical to teaching children to mastery. If students are placed in material that's too difficult for them, the amount that students have to learn is much greater than 10-15% of a lesson. They cannot master the material in a single day when there is too much that they do not know.
Students should be placed at a lesson where they can perform correctly on every item the first time they see it, at least 70% of the time for new material and 90% correct on the review material and applications that have been taught previously. If students have these first-time correct response rates, by the end of a lesson they will be able to learn the material they didn't get right the first time. Teachers will have enough time to correct errors that students make, and students will be able to absorb the new material presented in each lesson.
Teaching to mastery has several important benefits to students. Students who master material in a lesson can more easily learn new material. The skills and concepts students acquire provide a very strong foundation for learning new skills and concepts. Students' self-esteem increases when they master material presented to them. They are confident that they will be able to learn new material. They know they are successful. They look forward to going to school, participating in groups and doing their assignments.
IMPORTANT: Assigning students material they can't understand can be very punishing to them. Forcing a 3rd grade student with beginning decoding skills to read a grade-level text, for example, communicates to the student that s/he can't read nearly as well as many other 3rd graders. The overall message is that the student is deficient, which can lead to serious self-image problems. Students who are put in material that is too difficult for them often generalize from their experience and anticipate that they will fail on any new material they encounter. Conversely, students who are placed in material they can master in a reasonable amount of time develop very positive self-images. They anticipate that they will master any new material they encounter, and they are ready for the challenge!