{
  "name": "Forgetting curve data: Ebbinghaus 1885, the 2015 replication and the archived Waterloo page",
  "desc": "Forgetting curve data, one row per value. quoted_value holds figures quoted from the sources named in study and source_location; derived_value holds values computed by Feedback & Forgetting from the inputs named in formula. Ebbinghaus 1885 is in the public domain (author d. 1909). Values from Murre & Dros (2015), PLOS ONE, doi:10.1371/journal.pone.0120644, are licensed CC BY 4.0; they were re-keyed into one row per value and kept as printed (proportions). The Mack and Seitz values (Heller, Mack & Seitz 1991) are as reported in that paper. The Waterloo figures are quoted from an archived web page that cites no study. Quoted values are not covered by this site's CC BY 4.0 license; the publishers' terms apply. 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/forgetting-curve/",
  "from": [
    "Ebbinghaus, H. (1885). Über das Gedächtnis. Leipzig: Duncker & Humblot, pp. 91, 103, 105, 106, 109 (public domain)",
    "Murre & Dros (2015), PLOS ONE, doi:10.1371/journal.pone.0120644, Tables 1, 2 and 3 and Results (CC BY 4.0)",
    "University of Waterloo Counselling Services, “Curve of Forgetting”, archived copy of 2017-03-29"
  ],
  "how": "Compiled by Feedback & Forgetting from the data listed",
  "data_by": [
    "Ebbinghaus, H. (1885). Über das Gedächtnis. Leipzig: Duncker & Humblot. Public domain (author d. 1909)",
    "Murre, J. M. J., & Dros, J. (2015). Replication and analysis of Ebbinghaus' forgetting curve. PLOS ONE 10(7): e0120644, doi:10.1371/journal.pone.0120644, CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)",
    "University of Waterloo Counselling Services, “Curve of Forgetting”, archived copy of 2017-03-29 (quoted figures only)"
  ]
}