A crude outline of 'direct instruction' might run as follows: the teacher works directly with a group of pupils, rather than the pupils being given tasks on which they work without the teacher. Direct instruction is likely to include episodes in which the teacher imparts knowledge by 'telling' pupils. The teacher has knowledge, and uses 'direct' ways to ensure that pupils acquire it. Yet, the author argues, that unless direct instruction can be clearly and unambiguously specified, robust empirical research into its 'effectiveness' is simply not feasible. He contends that school leaders should be very concerned about this issue at a time when they may feel under considerable pressure to steer their staff in the direction of 'traditional' approaches to teaching, with which direct instruction in particular is often associated.