Spaced learning: What’s the best schedule for children’s lessons?


What is the “spaced learning” effect? If your child needs to learn something — and you want that learning to stick — the best approach is to distribute learning sessions over time. A single, long lesson is usually less effective than multiple, shorter lessons. Moreover, the ideal duration of a lesson may be much briefer than we realize — particularly for young children.

It’s one of the oldest, most reliable findings of cognitive psychology: We tend to learn things better — embed them more firmly in long-term memory — when we distribute study sessions over time.

Yet for many of us, this feels counter-intuitive. When we take the opposite approach — cramming lots of information into a single session — we may have the impression that we’re learning fast and efficiently.

The problem? This “massed practice” approach can indeed lead to immediate gains. But they fade just as fast. In effect, we’re just loading up short term memory. We aren’t encoding information that’s going to end up in long-term memory. So we forget most of what we’ve “crammed” within a day or two.

By contrast, distributed learning — spacing presentation of the material over time — can make the process feel less efficient. If we wait a few hours (or longer) between sessions, we notice that we have to work to remember what we learned about earlier. But these acts of effortful retrieval are what help us consolidate information into long-term memory (Brown et al 2014).

But how does this actually work? How long should a study session be? How much time should pass between sessions?

There isn’t any universal, one-size-fits-all answer. It depends on a student’s age, and on what he or she needs to learn. But research offers some rather surprising insights. For example, suppose you have a young child who is learning to read.

What’s the best schedule for honing early literacy skills?

Researchers tackled this question in an experimental study of 5-year-olds (Seabrook et al 2005). They provided all the students with a total of 6 minutes of reading instruction per day. But each child was assigned to one of two, different schedules:

  • Some children received their instruction in a single, 6-minute long session.
  • Other children received their instruction in three, separate, 2-minute long sessions, held at different times during the school day.

The researchers tracked the children’s progress, and administered a reading test at the study’s end.

Which kids improved the most? The children who had received the spaced, 2-minute long sessions.

This is just one example. It doesn’t mean that everybody will benefit from learning things in 2-minute bouts. Or that it’s always a good idea to hold multiple study sessions in a single day. On the contrary.

Different circumstances demand different strategies

For instance, if you’re an adult trying to learn new words in a foreign language — and you want to remember them 12 weeks later — experiments suggest you should space your initital learning sessions 4-12 hours apart (Kornmeier et al 2022). Then, for long-term retention, you can follow up with retrieval sessions every few days — or even wait a week or more.

While some researchers have reported best results for progressively lengthening delays between sesions (e.g., review on Day 3, Day 9, and Day 28 — Kang et al 2014); the evidence across studies indicates that this approach isn’t necessarily superior to spreading out sessions in a more uniform way (Latimier et al 2021).

If there’s an overarching principle to follow with spaced practice, it might be this: You need to wait long enough between sessions that you have to work to retrieve the previously learned information…yet not so long that you have forgotten it entirely (Latimier et al 2021; Brown et al 2014).

And what about the length of a learning or study session? What’s ideal?

That, too, depends. Are you feeling curious, interested, attentive? Then it probably makes sense to keep going. Otherwise, it makes sense to switch to another task — or at least take time to slow down and reflect on what you’ve been learning.

So there isn’t any single schedule that benefits everyone equally, in all situations. But there’s a relatively simple takeaway, a rule of thumb for children. Unless a child is really focused and enthusiastic about continuing a lengthy lesson, it’s probably better to break things up.

To see what I mean, consider an experimental study of 1st and 2nd graders, a study that presented kids with a series of brief biology lessons (Vlach and Sandhofer 2012).

Experiment: What’s the best schedule for teaching young students about science concepts?

In this study, each lesson was just 5 minutes long, and it followed the same format. The lesson began with an overview of information about food chains – general information that applies to food chains all over the world.

food-chain-arctic-by-BlueRingMedia-shutterstock-min.png.pagespeed.ce.w7BONvcw5h.png

Next, the lesson focused on the details of a food chain in a specific biome, like the Arctic, desert, ocean, grasslands, or swamp. The student learned about 5 different life forms in the biome, and the role that each life form played in the food chain.

All of the children participated in a total of four lessons. But each child was randomly-assigned to one of three different schedules:

  • 12 kids were selected to receive all four lessons on the same day;
  • 12 kids were selected to receive two lessons on two consecutive days, and
  • 12 kids were selected to complete just one lesson per day, for four days in a row.

Each child was tested on his or her knowledge before the study began, and again at the end – one week after his or her last lesson.

So what happened? How much had children learned?

The children who had received all four lessons in a single day retained almost nothing.

Their understanding of food chains had changed very little. Their test scores at the end of the study had increased only slightly from their baseline, pre-instruction scores.

The kids who completed two lessons each day showed greater growth – an improvement over the kids who’d had to cram all four lessons into one day.

And the biggest gains of all? Those belonged to the kids who had completed just one lesson per day. And these kids were especially advanced when it came to applying the concepts to novel situations.

For example, they performed much better than other kids on test questions that asked them to reason about cause and effect in a new, previously unstudied food chain. (“The grass gets sprayed with a poison that makes animals die when they eat it. What happens to the number of crickets. Does it go up, down, or stay the same?”)

So it appears that smaller doses of instruction – spread out over four days – were more effective than cramming the same amount of instruction into just one or two days.

Okay…but this was merely a single, small study. What other evidence is there in favor of the spaced learning effect?

Replication of the food chain study

Well, first of all, there’s this: The researchers repeated the food chain experiment on a new set of kids, and once again, the “one lesson per day” schedule was linked with the best learning outcomes. Students remembered more, and showed a greater understanding of the concepts (Gluckman et al 2014).

Spaced learning of math and history facts, and other verbal information

In addition, experimental studies indicate that spaced study sessions are a more effective way for kids to learn multiplication facts (Rea and Modigliani 1985), and retain history facts over the long-term (Carpenter et al 2009).

And for all sorts of verbal information, there is ample evidence for the advantage of spaced practice over “cramming.” Across more than 250 studies, people show better long-term recall when study sessions are spaced apart. A single, lengthy study session is almost never as effective as multiple, shorter sessions spread over time (Cepeda et al 2006).

Research tells us something else too: Spaced study sessions are especially successful when they include a testing component.

To see what I mean, let’s go back to the food chain studies.

Those 5-minute lessons weren’t just passive listening sessions. Kids did more than receive information. They also had to answer questions about the material. Questions testing their memory for the facts, and their comprehension of the concepts.

Many studies attest to the benefits of such testing. Learning is more likely to “stick” when we are forced to search our minds for answers. And it appears these benefits are magnified when we combine testing with spaced study sessions (Kang 2016).

More reading

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References: Spaced learning

Brown PC, Roediger HL, amd McDaniel MA. 2014. Make it stick: The science of successful learning. Belknap Press.

Carpenter SK, Pashler H and Cepeda NJ. 2009. Using tests to enhance 8th grade students’ retention of U.S. history facts. Applied Cognitive Psychology 23: 760-771.

Cepeda NJ, Pashler H, Vul E, Wixted, JT, and Rohrer D. 2006. Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin 132(3), 354.

Cepeda NJ, Vul E, Rohrer D, Wixted JT, Pashler H. 2008. Spacing effects in learning: a temporal ridgeline of optimal retention. Psychol Sci. (11):1095-102.

Gluckman M, Vlach HA, and Sandhofer CM. 2014. Spacing simultaneously promotes multiple forms of learning in children’s science curriculum. Applied Cognitive Psychology 28(2): 266–273.

Goossens NA, Camp G, Verkoeijen PP, Tabbers, HK, Bouwmeester S, and Zwaan RA. 2016. Distributed Practice and Retrieval Practice in Primary School Vocabulary Learning: A Multi‐classroom Study. Applied Cognitive Psychology 30: 700-712.

Kang SH. 2016. Spaced repetition promotes efficient and effective learning: Policy implications for instruction. Policy Insights from the Behavioral and Brain Sciences 3: 12-19.

Kornmeier J, Sosic-Vasic Z, Joos E. 2022. Spacing learning units affects both learning and forgetting. Trends Neurosci Educ. 26:100173.

Latimier A, Peyre H, and Ramus F. 2021. A meta-analytic review of the benefit of spacing out retrieval practice episodes on retention. Educ. Psychol. Rev. 33: 959–987 .

Rea CP and Modigliani V. 1985. The effect of expanded versus massed practice on the retention of multiplication facts and spelling lists. Human Learning: Journal of Practical Research & Applications 4(1): 11–18.

Rohrer D and Pashler H. 2007. Increasing retention without increasing study time. Current Directions in Psychological Science 16(4): 183-186.

Seabrook R, Brown GDA, Solity JE. 2005. Distributed and massed practice: From laboratoy to classroom. Applied Cognitive Psychology 19: 107-122.

Sobel HS, Cepeda NJ, and Kapler IV. 2011. Spacing effects in real-world classroom vocabulary learning. Applied Cognitive Psychology, 25: 763–767.

Varga NL, Bauer PJ. 2013. Effects of delays on 6-year-old children’s self-generation and retention of knowledge through integration. J Exp Child Psychol. 115(2):326-41.

Vlach HA, Sandhofer CM. 2012. Distributing learning over time: the spacing effect in children’s acquisition and generalization of science concepts. Child Dev. 83(4):1137-44.

Title image of girls with microscope by Rawpixel / shutterstock

Image of Arctic food chain by BlueRingMedia / shutterstock

Content of “The spaced learning effect” last modified 3/2024

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