Interleaving: A teacher's guide
Interleaving: A teacher's guide to using this study technique for better student memory and retrieval.
What Is Interleaving in Education?
Interleaving is a learning technique where students mix multiple topics or subjects during study sessions rather than focusing on one topic at a time. For example, instead of spending an entire period on fractions, a teacher might alternate between fractions, decimals, and percentages within the same lesson. This approach strengthens long-term retention and improves students' ability to distinguish between different problem types.
Interleaving is a learning technique in which learners mix, or interleave multiple topics or subjects while studying to improve their learning process.
Key Takeaways
- Beyond Flashcards: Why mixing topics beats blocked practice for long-term retention, even when students feel they're learning less
- The Difficulty Paradox: How making learning harder through interleaving challenges working memory and creates interference effects but actually strengthens memory and problem-solving skills in your classroom
- Practical Interleaving Strategies: Transform revision sessions by cycling through related topics instead of marathon single-subject study blocks
- The Exam Preparation Secret: Why schools using interleaved practice see better results, especially in subjects requiring deep understanding like maths
The theory proposes that for learning two or more related topics or concepts, it is better to alternate between them rather than focusing exclusively on one topic or concept at a time. For instance, if a student is learning about short-term difficulties of pollution in a geography project, the student would also study how to bring improvements in energy supply on the same day by mixing the two topics or by switching back and forth between them.
This study strategy has been linked to an improvement in memory and its popularity has grown as the beneficial effects have been documented by organisations such as the chartered college of teaching. Interleaving is a method of teaching where students learn concepts in different ways at different times. This approach helps them retain information better because they're not just memorizing facts and figures. They're actually thinking about the material and applying it to real life situations.
When you teach a concept through interleaving, you give students practice with the material before moving on to another topic. So when you teach a concept, you should spend some time explaining it, then move on to another concept. Then come back to the original concept later.
This process repeats itself throughout the course, giving students multiple chances to understand the material. Interleaving works well for topics that require deep understanding, such as algebra or calculus. But it doesn't work very well for subjects that are taught in bite-sized chunks, like reading comprehension or vocabulary.
To help students grasp these types of concepts, try interleaving during class time. Instead of lecturing on the same topic over and over again, break the lesson down into small pieces and let students discuss each piece individually. Afterward, bring the group together and review the entire concept.
Interleaving is an effective strategy for developing problem-solving and categorisation skills. Also, interleaving leads to enhanced long-term retention and increased ability to transmit learned knowledge.
Interleaving forces the deep brain stimulation for retrieving because each practice attempt is new, so rote responses used from short-term memory won’t help. Experts of Cognitive Psychology believe that interleaving improves the brain’s ability to discriminate or differentiate, between concepts and fortifies memory associations. Along with the application of spacing, schools are increasingly seeing this as an effective strategy for exam preparation. In this article, we will explore the implications for memory & cognition.
Why Does Interleaving Work Better Than Blocked Practice?
Research shows interleaving works because it forces students to constantly retrieve and apply different strategies, strengthening neural pathways. Studies by organizations like the Chartered College of Teaching demonstrate that while blocked practice feels easier and shows immediate gains, interleaved practice leads to superior long-term retention and transfer of knowledge. The difficulty students experience during interleaving actually signals deeper learning is occurring.
Many research studies have indicated that students learn better when they are repeatedly exposed to different interleaved or shuffled concepts, rather than blocked (Rohrer, 2012). In a study session, a student might feel that he had a more difficult time studying due to interleaving. But, in the long-term, he would end up learning better through interleaving.
Cognitive psychologists suggest that one shouldn’t study a single topic, idea, or similar type of problem for too long. It is recommended to change the topic often. Interleaving may seem more difficult than studying a single topic for a long time, but it is more beneficial in the long run (Kornell & Bjork, 2013).
Bjork R & Bjork E (2011) assessed the impact of adding two desirable difficulties in making the task easier. In their study, Bjork R & Bjork E (2011) focused on a relatively short-duration set of tasks provided in a single lesson and assessed how desirable difficulties affect the learning process of a topic.
Their study revealed that making things difficult in a positive manner, results in improved learning of the students. In another study conducted by Kornell & Bjork (2013), the researchers investigated whether interleaving can be used to improve the performance of students. The researchers compared three groups: Students who studied a single topic; students who studied two topics simultaneously; and students who studied two topics sequentially. They found that students who studied two topics concurrently performed significantly better than those who studied only one topic.
In another study, Rohrer (2012) examined the effect of interleaving on the performance of students. He found out that students who were taught using interleaving outperformed those who were taught using blocking.
The above mentioned studies provide evidence that interleaving helps in improving the overall performance of students. However, there is no conclusive proof that interleaving helps students retain information longer.
How Can Teachers Implement Interleaving in Daily Lessons?
Teachers can implement interleaving by cycling through related topics within single lessons and mixing problem types in homework assignments. Start by identifying 2-3 related concepts and alternate between them every 10-15 minutes, ensuring students practice switching between different solution strategies. For revision sessions, create mixed practice sets that include questions from multiple previous topics rather than focusing on just the most recent material.
There is no single correct way to use interleaving. Its effectiveness depends upon many factors such as learners' surrounding environment, the type of material involved, as well as learners' abilities and preferences. Hence, the learner needs to assess these factors and then decide when and how to interleave. It is also suggested to assess the effectiveness of the interleaved practice over time and experiment with multiple approaches to it.
To interleave during the study, learners should choose different topics and spread them all through their learning sessions. The concepts can be acquired from the same subjects or different subjects, but according to some experts of Educational Psychology, this strategy is most effective when the topics are related in some way.
For instance, in a study session, a learner could devote some time to Clinical Practice of Psychology, some time to Applied Cognitive Psychology, some time to Experimental Psychology and then start a new cycle with the Clinical Practice of Psychology, possibly reviewing the topics in a different sequence and using multiple study strategies.
Shuffling things up enables learners to retrieve information and create new connections amongst the concepts: for instance, how is a specific concept of Experimental Psychology relates to what was studied in Applied Cognitive Psychology? It must be ensured that the student devotes sufficient time to each topic. Each time a topic is studied, a deeper understanding is achieved. Students must not use interleaving as an excuse to shift to another subject if the current subject comes to be too challenging. Instead, they must continue to study one topic until they have a sense of achievement before switching to another topic.
Interleaving vs. Blocked Practice: What's the Difference?
Interleaving, which can be sometimes called mixed practice or varied practise, is different from blocked practise (also known as specific practice), which involves paying attention to just one type of practice or topic at a time. Short-duration auditory memory traces may last only a few seconds, which makes it harder to memorise the phonological traits of an earlier item. Hence, due to the short duration of auditory memory traces, blocking practice is more likely to lead to better pronunciation learning as compared to interleaving when proficiency was evaluated by way of either a recall test (Experiment) or multiple-choice tests (Experiments).
The main reason why interleaving helps memory is that it makes the brain work harder. When you are trying to memorize something, your mind works hard to make sense of what you are trying to remember. This is called active encoding. Active encoding requires a lot of mental effort. If you are constantly changing the way you think about the same thing, then you are engaging in passive encoding. Passive encoding doesn’t require much mental energy.
When you are actively engaged in thinking about something, you are creating a neural network in your brain. This neural network is made up of neurons which are connected to other neurons. These connections help us store memories. When we are passively engaged in thinking about something we are not creating any new neural networks. We are just reusing old ones.
This means that our brains don’t get as many opportunities to create new neural networks. As a result, our brains become less efficient at storing memories. This is where interleaving comes into play. By constantly switching between different ways of thinking about the same thing, you are creating more neural networks. This allows your brain to create more connections and therefore store more memories.
What Are the Main Benefits of Interleaving for Students?
Interleaving improves students' ability to identify which strategy to use for different problems, leading to better exam performance especially in subjects requiring deep understanding like mathematics. Students develop stronger discrimination skills between concepts and show improved transfer of learning to new situations. The technique also enhances long-term memory retention, with studies showing interleaved learners outperforming blocked learners on tests weeks or months later.
The benefits of using interleaving are attributed to Memory & Cognition. Interleaving is an effective learning strategy that includes retrieval practice. Therefore, it may seem harder than spaced practice. But, one must not forget that effortful studying may seem difficult but gives better results in long run. Benefits of interleaving may be seen in the conceptual learning of similar types of math problems (such as evaluating volumes of different shapes), similar categories of visual stimuli and confusing grammatical tenses.
In conclusion, if your students are studying for an exam, why would you choose to cram everything into one night instead of spreading it over several nights? Well, because when you spread it out like that, you have more time to review each section before going on to the next. This means you're able to retain information better and remember it longer. And since you're spending more time reviewing each section, you're also more likely to understand it fully.
Following are the most significant benefits of using Interleaving in education:
- Interleaving two tasks can enhance students' performance in both tasks as compared to practising each task separately, even when students spend an overall less time doing each task.
- Interleaved practise is especially useful for studying something that relates to problem-solving, like physics or math- interleaving helps select the right strategy to solve a problem.
- One significant mechanism that interleaving is regarded as being caused by, is contextual interference. An increased contextual interference, prompts students to use increased contrast between concepts and learning strategies, which helps students notice the similarities, differences and connections between concepts.
- Examples of Interleaving, from distinct categories can enhance learners’ technical skills more than practising with the examples of the same category each time.
- Interleaving different topics can help prevent the confusion that may arise from learning similar topics simultaneously.
- Interleaving has been associated with other benefits in education, such as an improved ability to identify mistakes, as well as an enhanced ability to focus and set goals.
- It is easy to implement interleaving because it mostly doesn’t require any special resources.
It can be said that interleaving offers a lot of help for the students in their learning process. These constructive effects make interleaving an effective learning strategy to be used by the students in a variety of situations.
Interleaving: FAQs for Teachers & Educators
1. What is interleaved learning?
Interleaved learning is a form of learning where different topics or skills are practiced in a mixed, or interleaved, sequence. This contrasts with blocked or massed practice, where one topic or skill is practiced repeatedly before moving on to the next. Interleaved learning is considered an effective learning technique as it encourages learners to differentiate between different topics or types of problems.
2. How does interleaved practice differ from massed practice?
In massed practice, learners focus on one topic or skill at a time, often for a long period. In contrast, interleaved practice involves switching between different topics or skills within a single study session. While massed practice can lead to quick short-term gains, research suggests that interleaved practice can improve long-term memory and learning outcomes.
3. How does interleaving affect memory capacity and long-term memory?
Interleaving can enhance memory capacity and long-term memory by promoting the process of discrimination. By practicing different topics or skills in an interleaved manner, learners are forced to recognize and remember the distinguishing features of each. This process can strengthen memory associations and improve recall over time.
4. How can I incorporate interleaved learning into my teaching practice?
Interleaved learning can be incorporated into teaching practice by designing lessons and practice sessions that mix different topics or types of problems. Instead of focusing on one topic for an extended period, switch between topics within a single lesson or study session. This can be done at various time periods, depending on the complexity of the topics and the learners' familiarity with them.
5. What does current study in Educational Psychology say about interleaved learning?
Current study in Educational Psychology suggests that interleaved learning can be a powerful tool for enhancing learning outcomes. However, it's important to note that the effectiveness of this learning technique can depend on several factors, including the nature of the material, the learners' prior knowledge, and the timing and structure of the practice sessions.
What Are Desirable Difficulties in Learning?
Desirable difficulties are learning challenges that slow down initial performance but enhance long-term retention and transfer of knowledge.
When students encounter desirable difficulties like interleaving, they must work harder to retrieve information and make connections between concepts. This increased cognitive effort strengthens neural pathways and creates more durable memories. Research by cognitive psychologists Robert and Elizabeth Bjork shows that while these difficulties make learning feel harder initially, they lead to superior outcomes compared to easier study methods.
What Is the Discrimination Hypothesis?
The discrimination hypothesis suggests that interleaving improves learning by helping students identify key differences between similar concepts or problem types.
When students study topics in blocks, they don't need to determine which strategy or formula to apply, they simply repeat the same approach. Interleaving forces learners to constantly compare and contrast different concepts, strengthening their ability to recognise when to apply specific knowledge. For example, alternating between area and perimeter problems helps students understand the distinct features of each calculation rather than mechanically applying formulas.
When Should Teachers Avoid Interleaving?
Interleaving works best for topics that share similarities but require different approaches. Avoid interleaving when teaching completely unrelated subjects or introducing brand new concepts.
Interleaving is most effective when:, Topics share underlying connections (like different mathematical operations), Students have basic familiarity with each concept, The goal is distinguishing between similar problem types, Building long-term retention matters more than immediate performance
Avoid interleaving when:, Introducing completely new material for the first time, Topics are entirely unrelated (like mixing chemistry with creative writing), Students lack foundational knowledge in the subject areas, Working with very young learners who need more structured practice
How Can Teachers Implement Interleaving in Daily Lessons?
Start small by mixing two or three related topics within a single lesson, gradually increasing complexity as students adapt to this approach.
Week 1-2 Implementation: Begin with homework assignments that alternate between two recently taught concepts. For instance, mix fraction and decimal problems rather than grouping them separately.
Week 3-4 Implementation: Introduce interleaving during class activities. Spend 15 minutes on concept A, switch to concept B for 15 minutes, then return to concept A with slightly different examples.
Week 5-6 Implementation: Design revision sessions that cycle through three or four related topics. Create mixed problem sets where students must identify which strategy to apply before solving.
Long-term Implementation: Build spiral curricula where previous topics regularly resurface alongside new material. Use starter activities that revisit concepts from weeks or months ago, maintaining and strengthening prior learning.
What Does Research Tell Us About Optimal Interleaving Schedules?
Research indicates that moderate interleaving produces better results than either pure blocking or excessive mixing of topics.
Studies suggest the most effective approach involves:, Introducing concepts initially through focused instruction, Beginning interleaving once students grasp basic principles, Maintaining a 3:1 or 4:1 ratio of interleaved to blocked practice, Spacing interleaved sessions across days or weeks rather than cramming
The optimal schedule depends on subject complexity and student readiness. Mathematics benefits from frequent interleaving of problem types, whilst language learning might require longer blocks before mixing grammar concepts.
How Can Schools Track the Impact of Interleaving?
Schools can measure interleaving effectiveness through delayed testing, transfer tasks, and comparing performance on mixed versus blocked assessments.
Assessment strategies include:, Testing retention after delays of one week, one month, and one term, Creating transfer problems that require applying knowledge in new contexts, Comparing scores on shuffled versus grouped question formats, Tracking student confidence and accuracy in identifying problem types, Monitoring performance on cumulative examinations versus unit tests
Document both immediate performance (which may initially decrease) and long-term retention (which should improve) to demonstrate interleaving's true benefits to stakeholders.
References and Further Reading on Interleaving
