The Learning Science Behind PlanexAI’s Study Tools

Summary

PlanexAI’s study tools are built on two methods that cognitive psychology consistently ranks among the most effective for durable learning: retrieval practice and spaced, or distributed, practice. This brief maps each tool in the product to the peer-reviewed evidence behind it, and states plainly what that evidence does and does not establish.

A framework for effective study

In a 2013 review for Psychological Science in the Public Interest, Dunlosky and colleagues assessed ten widely used study techniques and rated two as high in utility across the range of conditions they examined: practice testing and distributed practice^[1]. Several popular habits, including rereading and highlighting, were rated low. PlanexAI is built around the two techniques the review rated highest.

Retrieval practice: the testing effect

Retrieval practice, often called the testing effect, is the finding that recalling information strengthens memory more than reviewing it again. Roediger and Karpicke found that students who tested themselves on a passage retained substantially more a week later than students who reread it the same number of times^[2]. In a later experiment, repeated retrieval of foreign-language vocabulary produced large gains in long-term recall, while repeated study after initial learning did not^[3].

In PlanexAI, this is what flashcards, image-occlusion SmartCards, and quizzes are for. Each one asks you to produce the answer from memory rather than reread it, which is the condition the research shows improves retention.

Spaced repetition: the spacing effect

The spacing effect is the finding that reviews spread over time produce better long-term retention than the same reviews packed together. A meta-analysis by Cepeda and colleagues, covering 317 experiments, found that distributed practice reliably outperformed massed practice, and that the best gap between reviews widened as the target retention interval grew^[4].

PlanexAI schedules flashcard reviews with the Free Spaced Repetition Scheduler (FSRS), an open-source algorithm that models each card’s memory stability and retrievability and places the next review at the point where recall is beginning to fade^[5]. In practice, cards you find easy return less often and cards you struggle with return sooner, which is the spacing effect applied one card at a time.

Distributed study through planning

The same spacing principle applies above the level of a single card. Packing study into one session before an exam is massed practice; spreading it across several days is distributed practice, and it retains more^[4]. PlanexAI’s planner turns a syllabus into dated deadlines and study blocks across the term, which distributes work over time rather than concentrating it the night before. The planning layer and the flashcard layer apply the same finding at two different scales.

What this evidence does and does not show

These findings come from controlled studies of learning and memory, in laboratory and classroom settings. They establish that, on average, retrieval practice and spaced practice improve retention relative to rereading and cramming. They are not a claim that any one product, PlanexAI included, produces a specific grade improvement. We have not run controlled efficacy trials of the product itself. What we can say is that PlanexAI’s core study tools are designed around methods the research supports, and away from habits, such as rereading and highlighting, that it rates as weak^[1]. Results depend on how the tools are used.

Common questions

References

1. [1] Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students’ learning with effective learning techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4–58. https://www.psychologicalscience.org/publications/journals/pspi/learning-techniques.html
2. [2] Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255. https://journals.sagepub.com/doi/10.1111/j.1467-9280.2006.01693.x
3. [3] Karpicke, J. D., & Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966–968. https://web.mit.edu/jbelcher/www/learner/retrieval.pdf
4. [4] 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://digitalcommons.usf.edu/psy_facpub/1771/
5. [5] Open Spaced Repetition. Free Spaced Repetition Scheduler (FSRS): a spaced repetition algorithm based on the difficulty-stability-retrievability memory model. https://github.com/open-spaced-repetition/free-spaced-repetition-scheduler