Teach17

A lesson can appear to go brilliantly. Pupils answer questions correctly, complete the task and seem confident. A week later, however, much of the knowledge may be difficult to recall.

This is not necessarily a sign of poor teaching or weak effort. Forgetting is a normal part of learning. The forgetting curve reminds us that pupils usually need to revisit, retrieve and apply important knowledge several times before it becomes secure.

Here are 17 ways teachers can use the forgetting curve to improve long-term learning.

1. Expect pupils to forget

Teachers should not assume that something has been learned permanently because pupils understood it during one lesson.

Without further practice, new knowledge can quickly become difficult to retrieve. Effective teaching therefore includes planned opportunities to return to important ideas.

2. Do not confuse successful performance with secure learning

Pupils often perform well while an example, method or sentence starter is still visible.

The real test comes later, when the support has been removed. Check learning after a delay rather than relying only on what pupils can do at the end of the original lesson.

3. Avoid fixed claims about how quickly pupils forget

The forgetting curve is often presented using precise percentages, such as pupils forgetting a certain amount after one hour or one day.

These figures should be treated cautiously. The rate of forgetting depends on the pupil, the subject, the difficulty of the material, prior knowledge, attention and how well the idea was understood.

The curve is a useful model, not a universal timetable.

4. Revisit knowledge before it disappears completely

Important knowledge should return regularly throughout a course.

A concept taught in September should not remain untouched until an examination in May. Brief, well-planned revisiting can keep knowledge accessible and reduce the need for large amounts of relearning later.

5. Use retrieval rather than repeated rereading

Rereading notes can make information feel familiar, but familiarity is not the same as being able to remember it independently.

Ask pupils to close their books and recall what they know. They could write a definition, draw a diagram, list key facts or explain a process before checking their notes.

6. Build retrieval into the start of lessons

A short retrieval activity can help pupils reconnect with earlier learning and prepare for the new lesson.

This might include:

• four questions on mini whiteboards;
• a short brain dump;
• a diagram to label from memory;
• a key term to define;
• a calculation using an earlier method.

The activity should be brief, purposeful and linked to important curriculum knowledge.

7. Retrieve knowledge from different timescales

Retrieval should not focus only on the previous lesson.

A useful starter might include:

• one question from yesterday;
• one from last week;
• one from last half-term;
• one from a previous year;
• one prerequisite for the new topic.

This helps pupils retain older knowledge while continuing to learn new material.

8. Space practice over time

Studying the same material repeatedly in one session can produce rapid short-term improvement, but the learning may not last.

It is usually better to spread practice across several lessons. Pupils might revisit an idea after one day, one week, several weeks and then later in the term.

The exact gaps will vary, but the principle is simple: return to knowledge after some forgetting has begun.

9. Do not save revision until the end of the course

Revision should be part of normal teaching rather than a separate event before examinations.

Regular cumulative review means pupils are less likely to reach Year 11 and discover that large parts of Year 9 and Year 10 need to be taught again.

10. Focus retrieval on the most valuable knowledge

Teachers do not have enough time to revisit every detail equally.

Departments should identify the knowledge pupils will need repeatedly, including:

• essential vocabulary;
• core concepts;
• equations and units;
• important procedures;
• common diagrams;
• recurring misconceptions;
• prerequisite knowledge for future topics.

Retrieval should reflect curriculum priorities rather than become a collection of random quiz questions.

11. Use more than quizzes

Retrieval practice does not have to mean a five-question test every lesson.

Pupils could:

• reconstruct a timeline;
• sketch a graph;
• complete an equation;
• explain a concept to a partner;
• label a diagram;
• compare two ideas;
• correct a mistake;
• solve a mixed problem;
• write a paragraph from memory.

The important feature is that pupils attempt to retrieve knowledge before seeing the answer.

12. Make every pupil think

Asking one volunteer a question gives only one pupil retrieval practice.

Use strategies that involve everyone, such as mini whiteboards, silent written answers, cold calling after thinking time or asking all pupils to commit to an option before discussing it.

Retrieval is most effective when every pupil has to search their memory.

13. Give pupils enough thinking time

Teachers sometimes reveal answers too quickly when pupils hesitate.

A short pause gives pupils time to search their memory. This effort can strengthen learning, even when recall is not immediate.

However, pupils should not be left completely stuck. A clue, image, first letter or partially completed example may provide enough support to restart retrieval.

14. Correct errors quickly

Retrieval will sometimes produce incorrect answers. This is not a reason to avoid it, but errors need to be addressed.

After a retrieval task:

• reveal the correct answer;
• explain common mistakes;
• ask pupils to correct their work;
• give them another chance to answer;
• revisit frequently missed knowledge later.

Retrieval without feedback can leave misconceptions in place.

15. Connect new learning to existing knowledge

New information is easier to understand and remember when it connects to something pupils already know.

Before teaching a new concept, retrieve the knowledge that supports it. For example, before teaching electromagnetic induction, pupils might revisit magnetic fields, current, potential difference and energy transfers.

These connections make new learning less isolated and easier to retrieve later.

16. Mix old and new questions

Completing ten identical questions can make pupils appear fluent because they already know which method to use.

Mixed practice requires pupils to identify the correct knowledge or method for themselves. A set of questions might combine current content with earlier topics and similar concepts that pupils often confuse.

This usually feels harder, but it provides a more realistic test of understanding.

17. Plan for long-term learning

The forgetting curve should influence curriculum planning, homework, assessment and lesson design.

Teachers can support long-term memory by:

• spacing practice;
• using cumulative retrieval;
• revisiting prerequisite knowledge;
• checking learning after a delay;
• correcting misconceptions;
• connecting ideas;
• gradually removing support;
• applying knowledge in different contexts.

Teaching is not complete when pupils understand something for the first time. Important knowledge becomes secure when pupils successfully return to it, retrieve it and use it again and again.