{
  "name": "Best review gap for two test delays: quoted shares and gaps in days",
  "desc": "Best review gap for two test delays. Quoted values: figures in the quoted_value column are quoted from the publications in source_doi, at the table or page in source_location. They are not covered by this site's CC BY 4.0 license; the publishers' terms apply. Derived values: figures in derived_value were computed by Feedback & Forgetting from the inputs named in formula. License for this site's selection, arrangement, notes and derived values: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). read_level records how much of each source was read: full text, abstract only, or citation only. Checked 2026-11-06.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "Feedback & Forgetting",
  "url": "https://feedbackandforgetting.com/learning-memory/spaced-repetition/",
  "from": [
    "Cepeda, N. J., Vul, E., Rohrer, D., Wixted, J. T., & Pashler, H. (2008). Psychological Science 19(11): 1095–1102, doi:10.1111/j.1467-9280.2008.02209.x, abstract"
  ],
  "how": "Compiled by Feedback & Forgetting from the data listed",
  "data_by": [
    "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, doi:10.1111/j.1467-9280.2008.02209.x (abstract figures quoted)"
  ]
}