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The science

The science of learning, finally working for you.

01

The forgetting curve

You forget most of what you read — fast.

In 1885, Hermann Ebbinghaus tracked how quickly memory fades without review. The pattern he found — a steep early drop, then a long, slow tail — has held up in a modern replication almost exactly. Nibbler's daily bites are timed to interrupt that decline before it happens, not after.

~66% of freshly learned material can be lost within 24 hours if it's never revisited. Spacing it out flattens the drop.
90% 34% 20% 12% 20 min 1 day 6 days 31 days

Shape of the classic Ebbinghaus "savings" curve, replicated with modern methods. Values illustrate the well-documented decay; exact figures vary by person and material.

98.8% how closely the 2015 replication tracked Ebbinghaus's original 1885 curve — the same shape of forgetting, measured 130 years apart.

What the study did

A learner memorised lists of nonsense syllables and relearned them after gaps ranging from 20 minutes to 31 days, measuring how much easier the second pass was. The 130-year-old curve held up almost exactly — steep early loss, then a long, slow tail.

Murre, J. M. J., & Dros, J. (2015). Replication and Analysis of Ebbinghaus' Forgetting Curve. PLOS ONE, 10(7), e0120644. View article ↗

02

The spacing effect

A little each day beats cramming it all at once.

Researchers pooled hundreds of memory experiments and found the same result again and again: the same total study time, spread across several days, sticks far better than one long session. It's the reason Nibbler is built around a daily rhythm instead of an occasional binge.

839 head-to-head comparisons across 317 experiments — spaced practice beat cramming almost every time.
35% Massed · 1 sitting 79% Spaced · over days

Bubble size illustrates the direction of the effect. The headline figure is the weight of evidence behind it, not one trial's score.

150% the right gap between reviews can boost later recall by up to this much — versus no gap at all.
sweet spot cram 1 day 2 days 4 days 7 days 14 days GAP BETWEEN STUDY SESSIONS →

Recall climbs ~34% from cramming to a one-day gap, then declines only slightly out to two weeks — spacing has a sweet spot, not "more is always better" (Cepeda et al., 2009; 10-day test delay).

What the study did

A meta-analysis gathered every strong distributed-practice study it could find and analysed how the gap between reviews affects retention. The conclusion was clear: spread learning out, and widen the gaps as your goal date gets further away.

Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed Practice in Verbal Recall Tasks: A Review and Quantitative Synthesis. Psychological Bulletin, 132(3), 354–380. View article ↗
Sweet-spot figures: Cepeda et al. (2009), Experimental Psychology, 56(4), 236–246 ↗

03

What actually works

Of 10 popular study methods, two came out on top.

Five researchers reviewed the ten study techniques people use most and rated each one. Highlighting and re-reading — the two most common — barely moved the needle. Practice testing and spaced practice were the only two rated high-utility across ages, subjects and real classrooms. Those are exactly the two habits Nibbler is built around.

High utility Moderate Low utility
Practice testing Distributed practice Elaborative interrogation Self-explanation Interleaved practice Summarisation Highlighting / underlining Re-reading Keyword mnemonic Imagery for text learning

Utility ratings grouped as reported by the study's authors. Dot position reflects the high / moderate / low grouping, not a numeric score.

What the study did

The team assessed each technique on how well it generalises across learners, materials and settings — and whether it holds up in real classrooms, not just labs. Practice testing and spacing were the only two to earn top marks on every count.

Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving Students' Learning With Effective Learning Techniques. Psychological Science in the Public Interest, 14(1), 4–58. View article ↗

04

Bite-sized beats long-form

Attention falls off a cliff after about six minutes.

The largest study of its kind analysed 6.9 million video-viewing sessions and found engagement holds steady for about six minutes, then drops sharply no matter how long the video runs. Shorter is consistently more engaging — the clearest evidence for why Nibbler serves knowledge in short, finishable bites instead of long lessons.

6 min is roughly where median engagement peaks, measured across 6.9M real viewing sessions.
~6 min ceiling 93% 79% 49% 32% 23% 0–3 min 3–6 min 6–9 min 9–12 min 12 min+
6.9M viewing sessions analysed — across 862 videos in 4 courses. One of the largest studies of online attention ever run.

What the study did

Researchers analysed engagement across 862 videos on an online course platform, measuring how long students actually watched. Length was the biggest single factor — and the resulting advice was explicit: chunk lessons into segments under six minutes.

Also in the data

Production budget wasn't what held attention. Informal talking-head clips and hand-drawn "Khan-style" videos were more engaging than polished, pre-recorded studio lectures — a good fit for Nibbler's warm, personal style.

Guo, P. J., Kim, J., & Rubin, R. (2014). How Video Production Affects Student Engagement. Proceedings of the First ACM Conference on Learning @ Scale, 41–50. View article ↗

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