evocar
The science

What Evocar is built on — and what we don't claim

Evocar's study mechanics are based on two of the most consistently replicated findings in learning research: the spacing effect and retrieval practice. Here is that research, and — because the education market is full of overclaims — a list of popular claims we deliberately avoid.

Spaced repetition

Reviewing material at increasing intervals produces better long-term retention than massed review of the same total duration. This "spacing effect" is one of the oldest and most robust results in memory research, confirmed across hundreds of studies. A large quantitative synthesis of the verbal-recall literature (Cepeda et al., 2006) found spaced practice reliably outperforming massed practice across tasks and retention intervals.

Evocar schedules card reviews with a spaced-repetition algorithm in the tradition of open, published schedulers such as FSRS, timing each card's return based on your review history rather than a fixed drill order.

Retrieval practice (active recall)

Producing an answer from memory strengthens retention more than re-reading or re-recognizing it — the "testing effect." Karpicke and Roediger (2008) showed that repeated retrieval during learning drove long-term retention of foreign-language vocabulary far more than repeated studying; Roediger and Karpicke (2006) documented the broader effect and its history.

This is why Evocar uses cloze deletion inside full sentences and asks you to produce the missing word before the card flips. It is also where the name comes from: evocar, to call to mind.

Readability and design choices

Card text follows the readability findings that have held up under testing: a clean sans-serif face, text at 16px or larger, roughly 1.5–1.6 line spacing, slightly expanded letter spacing, and no italics for answer text. Research on fonts for readers with dyslexia (Rello & Baeza-Yates, 2013) found that ordinary sans-serif and roman fonts outperformed specialty fonts, and that spacing mattered more than letter shapes. Card state is signaled with a small colored border plus an icon and a text label — never color alone — so the interface works for colorblind users.

What we deliberately don't claim

  • No "ADHD font" or "dyslexia font" claims. Evidence for specialty fonts such as OpenDyslexic is weak to negative in controlled studies. Evocar uses ordinary, highly readable type and buys the real benefit — spacing — without the gimmick.
  • No "hard-to-read fonts boost memory" tricks. The "desirable difficulty" font effect has largely failed to replicate, and added reading effort works against sustained attention. Card text is kept maximally easy to read.
  • No color-psychology promises. You will not hear from us that a particular hue "triggers dopamine" or "boosts retention by X%." Color in Evocar has one job: marking card state at a glance to reduce decision friction. That is an interface-design benefit, not a neuroscience claim.
  • No guaranteed outcomes. The research above supports the methods Evocar uses. Individual results depend on the learner, the material, and consistency of practice.

References

  1. 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.
  2. Karpicke, J. D., & Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966–968.
  3. Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
  4. Rello, L., & Baeza-Yates, R. (2013). Good fonts for dyslexia. Proceedings of the 15th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS '13).
  5. FSRS — Free Spaced Repetition Scheduler, an open-source scheduling algorithm and research project. github.com/open-spaced-repetition

This page describes the research informing Evocar's design. It is educational information, not medical or psychological advice, and Evocar is not a treatment for ADHD or any condition.