Different locks, different keys: a painting about learning to choose an approach that fits.
Mixing a few related problem types can help learners recognize what a situation needs, rather than wait for someone to name the next step.
By Arbab Naseebullah Kasi, Chief Executive Officer - CEO, Feel Worldwide Foundation Inc.
A learner can finish a page of calculations correctly and still hesitate when the next page does not announce which formula to use. That hesitation deserves attention. It may reveal something the first page never asked the learner to practice.
Following a method and choosing a method are different responsibilities.
Consider this illustrative classroom moment. A worksheet is headed “Area of Rectangles.” Every question beneath it asks for an area. The student must remember the calculation and perform it accurately, but the heading has already made an important decision. On a later assignment, a question about fencing appears beside one about floor covering. Now the student must notice the difference between a boundary and a surface before calculating anything.
The missing skill is not necessarily effort, confidence or intelligence. It may be recognition: understanding what kind of problem is present and which approach fits it.
Interleaved practice is one way to create room for that recognition. Instead of completing a long block of one problem type before moving to another, learners encounter a planned mixture of types. The idea is not to make education chaotic. It is to stop the order of the exercises from quietly doing all the choosing.
Notice the clue the worksheet gives away
When practice is arranged in blocks, the next task often resembles the last. That arrangement can be useful for introducing an unfamiliar procedure and identifying where someone needs help. The difficulty comes when success within the block is treated as proof that the learner can select the procedure independently.
In a mixed set, the learner has to inspect the task again. Is this asking for a total, a difference, a rate or a relationship? Does the information support the method that worked a moment ago? What would make a different method appropriate?
Doug Rohrer's 2012 review of interleaving and similar concepts describes this distinction: when questions are grouped under one concept, students have fewer opportunities to discriminate among concepts. The review also warned that the evidence then available was limited. It offered a reason to investigate mixed practice, not a license to replace every teaching approach with it.
For a teacher, trainer or independent learner, the useful question is specific: which decisions does our practice arrangement currently make on the learner's behalf?
Sometimes the answer is a chapter heading. Sometimes it is a repeated sequence. Sometimes a tutor says “use percentages” before the learner has considered whether percentages are needed. Removing that clue for part of the practice can reveal a gap that another dozen identical exercises would leave hidden.
What a classroom experiment actually found
A preregistered, cluster-randomized study by Doug Rohrer, Robert Dedrick, Marissa Hartwig and Chi-Ngai Cheung involved 54 seventh-grade mathematics classes. Classes periodically received mostly interleaved or mostly blocked assignments across four months. Both groups then completed an interleaved review. On an unannounced test one month later, average scores were 61% for the interleaved group and 38% for the blocked group, a difference of 23 percentage points. The paper appeared online in May 2019 and in the January 2020 journal issue. Read the researchers' paper.
The same paper reports that teachers implemented the intervention without training and expressed support in an anonymous survey before learning the results. That is useful evidence about feasibility in this particular setting, separate from the test scores.
These results do not mean that every learner will improve by 23 points. They concern particular mathematics content, students and arrangements. Nor do they establish that a mixed worksheet alone can overcome missing instruction, inaccessible materials or unmet learning needs. They do show why the organization of practice deserves serious consideration alongside the amount of practice.
Mix decisions rather than distractions
Interleaving is not the same as answering a message, switching to a video, checking email and returning to homework. Those interruptions change the activity without necessarily helping the learner compare meaningful alternatives.
A practical mixed set stays focused on a learning purpose. The problems differ in the approach they require, while the learner works through them with sustained attention.
For example, an illustrative mathematics set might combine finding the perimeter of a rectangle, finding its area, and determining a missing side from a stated area. These tasks share familiar objects but ask different questions. A useful prompt before calculation is: “What are you being asked to find, and what information makes your chosen method appropriate?”
The explanation can be brief. A sentence, diagram or spoken response may be enough. The aim is not to attach an essay to every exercise. It is to hear the decision that would otherwise remain invisible.
For workplace learning, the same design question can inspire a cautious local experiment. A spreadsheet workshop might present situations requiring a total, a filtered total or a count. Participants could first explain which operation fits the request. This is an illustrative adaptation, not a claim that the school mathematics study proved a workplace benefit. A trainer should test whether the adaptation helps their own learners perform the actual task.
Do not turn a useful idea into a universal rule
The material matters. A 2019 meta-analysis by Matthias Brunmair and Tobias Richter examined 59 studies and found an overall advantage for interleaving, but substantial differences across learning materials. The findings favored interleaving for some visual and mathematical tasks. Results for explanatory texts were ambiguous, while the word-learning studies favored blocked presentation overall.
That variation is a reason to choose thoughtfully. It is not a reason to force every reading session, vocabulary exercise or practical skill into the same pattern.
Before changing practice, ask whether learners already have enough understanding to attempt the component tasks. If someone has never been taught how to calculate an area, mixing area with three other unfamiliar procedures does not supply the missing explanation. Teach, demonstrate and support first where needed. Then introduce a manageable opportunity to choose.
This is a practical sequencing recommendation rather than a claim that one fixed ratio of blocked and mixed work has been established as best. There is no reason to promise a universal number of questions, minutes or repetitions.
Watch the nature of the difficulty. A learner who can explain the right method but makes an arithmetic slip needs different help from a learner who chooses the wrong method. A learner who cannot read the question clearly may need accessible presentation, not a more demanding practice schedule. Difficulty is information, but difficulty alone is not evidence of learning.
Make the reason for each correction visible
Mixed practice is most useful when mistakes lead somewhere. Marking an answer wrong without discussing the choice can leave a learner repeating the same misunderstanding in a different order.
Consider an illustrative error: a student adds the lengths around a rectangle when asked how much flooring will cover it. Simply replacing the answer with the area calculation corrects the page. Asking what flooring covers helps correct the decision.
A short review might distinguish three things. Did the learner understand the request? Did they select an appropriate method? Did they carry out that method accurately? These are proposed review questions, not a diagnostic instrument, but they can keep feedback from collapsing every error into “try harder.”
Ask the learner to compare the mistaken choice with the better one. What feature of the task rules out the first approach? What change to the question would make that approach suitable? This turns an error into a boundary between ideas rather than a verdict on ability.
Keep that conversation respectful. A person who pauses to reconsider may be doing more independent thinking than someone who moves quickly through a familiar sequence. Equally, repeated confusion should not be romanticized as productive struggle. Adjust the explanation, reduce the number of competing task types or provide another supported example when the learner needs it.
Build a small practice set you can learn from
Start with two or three related task types that learners have already encountered. Choose examples with a clear purpose, and write an answer guide that explains the choice of method as well as the result. Check that more than one approach is not being unfairly treated as wrong.
Use a short mixed section within an existing session rather than redesigning the entire course at once. Explain the change plainly: “These questions need different approaches. Before solving each one, decide what it asks you to do.” Keep the purpose visible without labeling every question with its solution method.
Review the work together. Record recurring confusions at the level needed to improve teaching, without making a public ranking of participants. If several people mistake a count for a total, the next lesson has a useful focus. If the instructions themselves are ambiguous, repair the instructions before attributing the problem to learners.
Return later with different examples of the same underlying decisions. Do not judge the approach only by how smooth the first session felt. Look for whether learners can choose appropriately when the original sequence and familiar wording are gone.
For a small training group, those observations can guide improvement, but they will not by themselves prove a causal effect. Attendance, prior knowledge, extra help and differences in the questions may influence the result. Keep the conclusion proportionate: this arrangement helped these learners with these tasks, or it needs revision.
Leave learners with a choice they can explain
Education becomes more useful when people can recognize where their knowledge belongs. Outside a lesson, a problem seldom arrives with the chapter title attached. Someone must decide what matters, what information is missing and what kind of response makes sense.
A carefully chosen mixture of practice tasks can give learners a chance to rehearse that responsibility. It need not be elaborate. A few well-designed contrasts, a reason for each choice and a later opportunity to try again can make the teaching conversation more revealing.
The purpose is not to make every task harder. It is to make independent judgment part of what we teach, rather than something we hope will appear after enough repetition.
Feel Worldwide Foundation Inc. welcomes conversations about possible partnerships that support practical learning and community opportunity. To explore a proposal or support the Foundation's mission through a donation, visit Feel Worldwide Foundation Inc. Any proposed collaboration depends on mutual fit and review.
Where in your own learning or teaching could you practice choosing the right approach, instead of being told which approach comes next?
