Imagine a classroom of 45 students in Liberia. A teacher spends 5 minutes demonstrating 37 + 24 on the blackboard. She then leads students through a 10-minute guided practice of a similar problem, 44 + 19. Finally, students launch into a 25-minute independent practice. All students work hard: 15 answer most questions correctly, 15 do okay, and 15 answer most questions incorrectly. The teacher circulates to give feedback to as many students as possible before the lesson ends.
Most pedagogical experts would recognise this as an instructionally sound, well-aligned 40-minute lesson. After many years of crafting lessons this way, I too believe this is a much more effective approach than status quo lessons in many low and middle-income countries — which is often a teacher lecturing and students copying from the board. However, after studying Direct Instruction (DI) programs, I now think that this Liberia math lesson falls far short of maximising the impact of 40 minutes of instructional time.
The pervasive textbook flaw
Before diving into why most 40-minute lessons are inefficient, let's revisit the pervasive flaw from Why Most Textbooks are Broken. From lesson to lesson, status quo textbooks move on to new learning goals without ever revisiting the old ones. This fails to leverage the known cognitive benefits of spacing and risks leaving students' misunderstandings unaddressed. These gaps persist and accumulate over time.
The textbook flaw, stated simply: most lessons are mostly 'new' material. DI program scope and sequences fix this by ensuring each learning goal is practised over many lessons. The fix: most lessons are mostly 'review.'
The problem with this lesson structure
Let's go back to our Liberian math class. The problem with the structure is twofold. First, 25 minutes of independent practice on a single goal means students who are making mistakes will likely repeat them. Some common mistakes when learning to regroup:
- Student A added a place value column where it doesn't exist.
- Student B forgot to add what was regrouped.
- Student C reversed the digits to be regrouped.
Students who are incorrectly answering 15 regrouping questions in a row are embedding these misunderstandings into memory. While the 25-minute practice is productive for the students answering correctly, it is actively harmful to students answering most questions incorrectly.
A second inefficiency: when students make a wide variety of errors, it is more difficult for the teacher to respond because she must diagnose many different mistakes simultaneously — particularly challenging for novice teachers seeing the errors for the first time.
The fix: use one lesson to practise several goals
A single DI lesson might have 10 different exercises, each focused on a different learning goal, 8 or 9 of which are review. Designing instruction in bite-sized chunks and spacing out practice sets the stage for exercises that are technically sound enough to prevent students from making a wide variety of mistakes, and purposeful enough to let teachers notice very specific details about student performance.
Neither inserting a mixed review lesson the day before a cumulative test, nor adding 5 minutes of review at the start of a lesson, is a sufficient pathway to maximise the full potential of 40 minutes of instructional time. The fix requires redesigning the lesson structure itself.
Studying DI programs and the theory of instruction behind them is a good place to start. Solving the global learning crisis inherently requires establishing a clear set of best practices for instructional design. Identifying the flaws does not require technical expertise. Fixing them does — and it is worth the effort.