File:Stability increase function.png: Difference between revisions

{{Fig|[https://supermemo.guru/wiki/Stability_increase Stability increase] function as computed by [[Algorithm SM-17]]. The function takes three arguments: (1) [[Glossary:Stability|stability]] at review expressed in days (on the left), (2) [[Glossary:Retrievability|retrievability]] at review (on the right), and (3) memory [https://supermemo.guru/wiki/Complexity complexity] expressed as [[Glossary:Item|item]] [[Glossary:Difficulty|difficulty]] (slider labelled '''Diff''' currently set at 0.8). In the picture, stability increase peaks at around 15 (vertical axis). For some levels of [[Glossary:Stability|stability]] and [[Glossary:Retrievability|retrievability]], the function drops below 1.0 indicating a decrease in [[Glossary:Stability|stability]] (e.g. due to premature review evoking the [[Glossary:Spacing effect|spacing effect]] in massed presentation). 61,768 repetitions of relatively [[Glossary:Difficulty|difficult]] [[Glossary:Item|item]]s were needed to produce this graph (at Diff{{=}}0.8). The longest [[Glossary:Interval|interval]]s reach around 14 years ([[Glossary:Stability|stability]] quantile 5172)}}