The science

Test prep, backed by cognitive science.

Most prep is folklore: cramming, tricks, and recycled PDFs. Ours is built on three findings from decades of learning research, and you can see each one at work in the product.

Retrieval practice
Thousands of questions, because recall beats re-reading.
Spaced repetition
A plan that paces review across days, not one cram session.
Immediate feedback
Detailed explanations the second you answer.
Principle 01 · Retrieval practice

You remember what you retrieve.

Re-reading a textbook feels productive, but it barely sticks. Pulling an answer out of your own head is what builds durable memory. In a landmark 2006 study, students who tested themselves remembered about 50 percent more a week later than students who re-read. That is why Test Ninjas is built around thousands of exam-style questions instead of passive review. Every problem set is retrieval practice.

ResearchRoediger & Karpicke (2006): self-testing retained ~50% more after one week.
Test Ninjas Retrieval practice screen
Hundreds of question-type problem sets, ready to drill.
Principle 02 · Spaced repetition

Space it out,
remember it longer.

Cramming everything into one night is the least efficient way to learn. Reviewing the same material at growing intervals moves it into long-term memory. Cepeda and colleagues (2006) reviewed the research and found spaced study consistently beats massed practice. Your personalized study plan paces lessons, targeted problem sets, and full-length tests across days instead of hours, and keeps resurfacing your weakest areas.

ResearchCepeda et al. (2006): spaced practice consistently outperforms cramming.
Test Ninjas Spaced repetition screen
A study plan that paces your review and targets your weakest areas.
Principle 03 · Immediate feedback

Learn the moment you miss.

Finding out you were wrong a week later does nothing. Immediate, detailed feedback lets you fix a misconception while it is still fresh. The instant you answer a question, Test Ninjas tells you whether you were right and, more importantly, why, including why each wrong choice is wrong. Every question turns into a small lesson instead of a guess.

ResearchImmediate feedback measurably improves learning and error correction.
Test Ninjas Immediate feedback screen
Every question comes with a full explanation, right and wrong answers alike.
Peer-reviewed

Backed by the research, not our opinion.

  1. [1]Roediger, H. L., & Karpicke, J. D. (2006). Test-Enhanced Learning: Taking Memory Tests Improves Long-Term Retention. Psychological Science, 17(3), 249–255.
  2. [2]Roediger, H. L., & Karpicke, J. D. (2006). The Power of Testing Memory: Basic Research and Implications for Educational Practice. Perspectives on Psychological Science, 1(3), 181–210.
  3. [3]Karpicke, J. D., & Bauernschmidt, A. (2011). Spaced retrieval: Absolute spacing enhances learning regardless of relative spacing. Journal of Experimental Psychology: Learning, Memory, and Cognition, 37(5), 1250–1257.
  4. [4]Soderstrom, N. C., & Bjork, R. A. (2015). Learning Versus Performance: An Integrative Review. Perspectives on Psychological Science, 10(2), 176–199.
  5. [5]Mettler E, Burke T, Massey CM, Kellman PJ. Comparing Adaptive and Random Spacing Schedules during Learning to Mastery Criteria. Cogsci. 2020 Jul-Aug;2020:773-779.
  6. [6]Yang BW, Razo J, Persky AM. Using Testing as a Learning Tool. Am J Pharm Educ. 2019;83(9):7324. doi:10.5688/ajpe7324

Prep the way memory actually works.

Retrieval, spacing, and instant feedback, built into every question you practice.

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