Editing Spaced repetition (section)

==Evidence and criticism==
Spaced repetition is wildly accepted as a performant learning strategy in a number of domains,<ref name=":0">{{Cite journal |last1=Latimier |first1=Alice |last2=Peyre |first2=Hugo |last3=Ramus |first3=Franck |date=2021-09-01 |title=A Meta-Analytic Review of the Benefit of Spacing out Retrieval Practice Episodes on Retention |url=https://link.springer.com/article/10.1007/s10648-020-09572-8 |journal=Educational Psychology Review |language=en |volume=33 |issue=3 |pages=959–987 |doi=10.1007/s10648-020-09572-8 |issn=1573-336X}}</ref><ref>{{Cite journal |last1=Bego |first1=Campbell R. |last2=Lyle |first2=Keith B. |last3=Ralston |first3=Patricia A. S. |last4=Immekus |first4=Jason C. |last5=Chastain |first5=Raymond J. |last6=Haynes |first6=Lora D. |last7=Hoyt |first7=Lenore K. |last8=Pigg |first8=Rachel M. |last9=Rabin |first9=Shira D. |last10=Scobee |first10=Matthew W. |last11=Starr |first11=Thomas L. |date=2024-02-07 |title=Single-paper meta-analyses of the effects of spaced retrieval practice in nine introductory STEM courses: is the glass half full or half empty? |journal=International Journal of STEM Education |volume=11 |issue=1 |pages=9 |doi=10.1186/s40594-024-00468-5 |doi-access=free |issn=2196-7822}}</ref><ref name=":1">{{Cite journal |last1=Kim |first1=Su Kyung |last2=Webb |first2=Stuart |date=March 2022 |title=The Effects of Spaced Practice on Second Language Learning: A Meta-Analysis |url=https://onlinelibrary.wiley.com/doi/10.1111/lang.12479 |journal=Language Learning |language=en |volume=72 |issue=1 |pages=269–319 |doi=10.1111/lang.12479 |issn=0023-8333}}</ref> with many researchers suggesting implementing this method in formal education.<ref>{{Citation |last1=Carolina E. |first1=Melody Wiseheart |title=Enhancing the Quality of Student Learning Using Distributed Practice |date=2019 |work=The Cambridge Handbook of Cognition and Education |pages=550–584 |editor-last=Dunlosky |editor-first=John |url=https://www.cambridge.org/core/books/abs/cambridge-handbook-of-cognition-and-education/enhancing-the-quality-of-student-learning-using-distributed-practice/88D92B0BC94535226DB7B39C8026EF31 |access-date=2025-05-10 |series=Cambridge Handbooks in Psychology |place=Cambridge |publisher=Cambridge University Press |doi=10.1017/9781108235631.023 |isbn=978-1-108-41601-6 |last2=Küpper-Tetzel |first2=undefined |last3=Weston |first3=Tina |last4=Kim |first4=Alice S. N. |last5=Kapler |first5=Irina V. |last6=Foot-Seymour |first6=Vanessa |editor2-last=Rawson |editor2-first=Katherine A.}}</ref><ref>{{Cite journal |last=Kang |first=Sean H. K. |date=2016-03-01 |title=Spaced Repetition Promotes Efficient and Effective Learning: Policy Implications for Instruction |url=https://journals.sagepub.com/doi/10.1177/2372732215624708 |journal=Policy Insights from the Behavioral and Brain Sciences |language=EN |volume=3 |issue=1 |pages=12–19 |doi=10.1177/2372732215624708 |issn=2372-7322}}</ref> There is evidence that the popular method of "expanding intervals" (when the interval between the repetitions increases with each repetition) performs as well as or better than uniformly spaced repetitions. Some papers find expanding intervals to be beneficial for recall, <ref>{{Cite web |title=Effect of uniform versus expanding retrieval practice on the recall of physiology information |url=https://www.researchgate.net/publication/221882038 |website=ResearchGate}}</ref><ref name=":1" />. Other meta-analyses tend to conclude that both methods yield similar results, therefore concluding that "strong recommendations to teachers and students in favor of spaced retrieval practice are warranted".<ref name=":0" /> 

Several mechanisms were suggested for expanding intervals providing an additional benefit; the most notable one is that one of the core tenants of spaced repetition is that spacing increases the effort for retrieval, and that expanding intervals allow to gradually increase that difficulty. However, little evidence has been found to back this claim. It has been argued that the benefit observed for expanding intervals in some studies is due to other factors, such as the timing of the first retrieval, the number of repetitions or the overall spacing between the tests.<ref name="Karpicke-2007" /><ref name="K&B" /> It has also been proposed that the best schedule is learner-dependent, making general recommendations irrelevant.<ref>{{Cite journal |last1=Tabibian |first1=Behzad |last2=Upadhyay |first2=Utkarsh |last3=De |first3=Abir |last4=Zarezade |first4=Ali |last5=Schölkopf |first5=Bernhard |last6=Gomez-Rodriguez |first6=Manuel |date=2019-03-05 |title=Enhancing human learning via spaced repetition optimization |journal=Proceedings of the National Academy of Sciences |volume=116 |issue=10 |pages=3988–3993 |doi=10.1073/pnas.1815156116 |doi-access=free |pmc=6410796 |pmid=30670661|bibcode=2019PNAS..116.3988T }}</ref>