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Daily Review · the science

Why review beats cramming

Memory fades on a schedule. So does the fix.

What you learn today, you start losing tomorrow — and the drop is steepest at first. The fix isn't studying harder; it's coming back at the right moment, just as a fact starts to slip. A few well-timed reviews hold something far longer than one long cram. Here's the curve behind Daily Review — and the studies that back it.

The curve
How fast does a memory fade?
The spacing
When should it come back?
The test
Why does recalling beat rereading?
See it happenflip the toggle

How the schedule decidesget it → the gap grows
The spacing ladder1 → 3 → 7 → 14 → 30 days
Each card sits on a ladder of gaps: 1 → 3 → 7 → 14 → 30 days. Get it right and it climbs to the next rung, coming back later — right as it starts to fade. Miss it and it drops back to 1 day, so you see it again soon. That's the whole engine: the schedule chases the forgetting curve, stretching each gap a little every time the memory holds. Newer tools (the open-source FSRS scheduler, built on the classic SM-2 method) fine-tune the gaps to you — but the idea is the same.
For fellowstested in medical training

These studies test the method, not this app — ClearShifts just puts an approach with a track record into your day.

Open today's reviewFlip the cards due today — this is the schedule, working. See your memoryWatch the same curve add up across what you've studied.

References

Bjork, R. A. (1994). Memory and metamemory considerations in the training of human beings. In J. Metcalfe & A. Shimamura (Eds.), Metacognition: Knowing about knowing (pp. 185–205). MIT Press.

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. https://doi.org/10.1037/0033-2909.132.3.354

Cepeda, N. J., Vul, E., Rohrer, D., Wixted, J. T., & Pashler, H. (2008). Spacing effects in learning: A temporal ridgeline of optimal retention. Psychological Science, 19(11), 1095–1102. https://doi.org/10.1111/j.1467-9280.2008.02209.x

Ebbinghaus, H. (1913). Memory: A contribution to experimental psychology (H. A. Ruger & C. E. Bussenius, Trans.). Teachers College, Columbia University. (Original work published 1885)

Kerfoot, B. P., Baker, H. E., Koch, M. O., Connelly, D., Joseph, D. B., & Ritchey, M. L. (2007). Randomized, controlled trial of spaced education to urology residents in the United States and Canada. The Journal of Urology, 177(4), 1481–1487. https://doi.org/10.1016/j.juro.2006.11.074

Kerfoot, B. P., DeWolf, W. C., Masser, B. A., Church, P. A., & Federman, D. D. (2007). Spaced education improves the retention of clinical knowledge by medical students: A randomised controlled trial. Medical Education, 41(1), 23–31. https://doi.org/10.1111/j.1365-2929.2006.02644.x

Landauer, T. K., & Bjork, R. A. (1978). Optimum rehearsal patterns and name learning. In M. M. Gruneberg, P. E. Morris, & R. N. Sykes (Eds.), Practical aspects of memory (pp. 625–632). Academic Press.

Martinengo, L., Ng, M. S. P., Ng, T. D. R., Ang, Y.-I., Jabir, A. I., Kyaw, B. M., & Tudor Car, L. (2024). Spaced digital education for health professionals: A systematic review and meta-analysis. Journal of Medical Internet Research, 26, e57760. https://doi.org/10.2196/57760

Maye, J. A., & Hurley, F. (2026). The effectiveness of spaced repetition in medical education: A systematic review and meta-analysis. The Clinical Teacher, 23(2), e70353. https://doi.org/10.1111/tct.70353

Roediger, H. L., III, & Karpicke, J. D. (2006). The power of testing memory: Basic research and implications for educational practice. Perspectives on Psychological Science, 1(3), 181–210. https://doi.org/10.1111/j.1745-6916.2006.00012.x

Woźniak, P. A. (1990). Optimization of learning [Master's thesis, Poznań University of Technology]. SuperMemo.