Retrieval Practice Is Costly For Some Students


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How do teachers ensure retrieval practice has notable benefits for all learners?

New research suggests the effect of working memory using retrieval practice only emerges when the task challenges WM capacity.

Using retrieval practice with different learners

Retrieval Practice Is CostlyIn a new 14-page paper, published by Zheng et al. (October 2022), research explores the inconsistency regarding the effect of working memory capacity on the testing effect – otherwise known as retrieval practice.

The typical finding is that in the final test (exam), items practised in the test condition (e.g. mock exam) are better than those in a restudy condition (day-to-day classroom).

This research poses an interesting conundrum: it is unclear whether testing should be uniformly applied in the classroom and whether testing help certain subpopulations more than others.

This raises some important questions for teachers working with various students (gifted, pupil premium, special educational needs etc) who are more successful than others in certain learning conditions.

Whilst many teachers are excited about the benefits of retrieval practice, if we stop for a moment to consider the various needs of our students in our classrooms, we should not be surprised to learn that students with a lower working memory capacity will benefit less from retrieval practice in certain scenarios.

For example, Monday morning or Friday afternoon? During detention or high-stakes exam? In English, maths or an Art lesson they love or loathe?

Methodology used

This research lasted four weeks, with each participant completing a visual search task over 9 sessions in the first 3 weeks of the trial. Spaced practice was used at various intervals (more details can be found on page 3-5).

Thirty-five undergraduate students – note, not classroom pupils – took part in the study with 33 participants required to achieve 80% success. All students spoke Chinese as their first language and two participants were excluded because of low accuracy in the final test.


The research suggested that “people with abundant working memory resources benefited from retrieval practice regardless of the stimulus frequency.”

Conversely, people with a lower working memory tended to have a “negative testing effect” and “demonstrates that retrieval practice is a costly learning technique.” The research suggests that a bottleneck of working memory emerges only when the demands of working memory exceed the working memory capacity.

Older people benefited from testing when feedback was provided but learned better through restudying than testing when no feedback was provided (Tse et al., 2010).

Two hypotheses are offered with my questions for teachers to consider below:

The first, that that the only benefit of retrieval attempt is for memories to be fully strengthened as long as the correct targets are retrieved. The second? That learners can benefit from re-encoding correctly retrieved information. The research writes that “successfully recalled associations may not be fully strengthened if WM resources are depleted during the retrieval attempt.”

Recommendations for teachers

  1. How should teachers adapt retrieval practice techniques for disadvantaged pupils?
  2. When should retrieval practice be used?
  3. Why should a retrieval practice quiz be adapted for different abilities?
  4. Do online quizzing platforms consider the working memory of the pupils using the software?
  5. What in-house research can schools conduct to learn how retrieval hinders or supports various learners?

Successfully retrieving the item does NOT guarantee that the memory is more effectively strengthened than restudying the item. (Zheng et al., 2022)