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SuperMemo Desktop
Developer(s) SuperMemo World
Stable release version 2013 (v. 16.00) November / November 2013; 2 years ago (2013-11)
Operating system Windows, Windows Mobile, Palm OS, Web, more
Type Accelerated learning and memory software
License Proprietary

SuperMemo (from "Super Memory") is a learning method and software package developed by SuperMemo World and SuperMemo R&D with Piotr Woźniak in Poland from 1985 to the present.[1] It is based on research into long-term memory, and is a practical application of the spaced repetition learning method that has been proposed for efficient instruction by a number of psychologists as early as in the 1930s.[2] The authors of the learning method and lead programmers of the software are Dr Edward Jacek Gorzelańczyk and Dr Piotr Woźniak.[citation needed]

According to proponents of the spaced repetition learning method such as Piotr Woźniak, it can optimize measured long-term knowledge acquisition.[3][4]

The method is available as a computer program for Windows, Windows CE, Windows Mobile, (Pocket PC), iPhone, iPad, iPod Touch, (iTunes), Palm OS (PalmPilot), etc. It can also be used in a web browser or even without a computer.[5]

The desktop version of SuperMemo (since v. 2002) supports incremental reading.[6]

Software implementation[edit]

The software implementation of the SuperMemo algorithm in its most rudimentary and basic form is a database of question and answer (Q&A) fields (or more practically, digital and electronic flashcards).[7] The database is either a pre-made collection, self-made, or in some cases both through Merging.[citation needed]

The software then traverses with the user through each element that is scheduled for repetition (a new set of "reps" is computed for each day on the calendar).[citation needed] The program gathers information about the user's memory through their responses and grades to their active recalls (conscious response to their questions – giving a conscious answer as opposed to passive review).[citation needed]

In three steps, the user reviews the card as follows:

  1. The user is given a question by SuperMemo
  2. The user responds with an answer from his own mind (active recall)
  3. The user gives himself a grade of what best reflects his recall. (A–E grade, or 5–0 grade, depending on what version and/or platform).

SuperMemo then calculates the needed intervals for proposed repetitions of one item or flashcard.[citation needed]


The specific algorithms SuperMemo uses have been published, and re-implemented in other programs.

Different algorithms have been used; SM–0 refers to the original (non-computer-based) algorithm, while SM-2 refers to the original computer-based algorithm released in the 1987 (used in SuperMemo versions 1.0 through 3.0, referred to as SM-2 because SuperMemo version 2 was the most popular of these).[8] Subsequent versions of the software have further optimized the algorithm.

SuperMemo currently uses SM-15.

Criticism of SM3+[edit]

The SM-2 algorithm uses the performance on a card to schedule only that card, while SM-3 and newer algorithms use card performance to schedule that card and similar cards. The additional optimizations sometimes yield perverse results – answering "hard" on a card may yield an interval longer than answering "easy" on a card – and are criticized as reducing the robustness of the algorithm, making it more sensitive to variations – non-uniform difficulty of cards (a problem in versions 4 to 6, according to Wozniak), inconsistencies in studying, and so forth.[9]

Wozniak disagreed with the criticism, but noted that in practice the other factors affecting study make it not very important.[10]

Non-SuperMemo implementations[edit]

Some of the algorithms have been reimplemented in other, often free programs such as Anki, Mnemosyne, and Emacs Org-mode's Org-drill. Full list of flashcard software.

The SM-2 algorithm has proven most popular in other applications, and is used (in modified form) in Anki and Mnemosyne, among others. Org-drill implements SM-5 by default, and optionally other algorithms such as SM-2.


  1. ^ Wolf, Gary (2008), "Want to Remember Everything You'll Ever Learn? Surrender to This Algorithm", Wired Magazine 
  2. ^ Spitzer, Herbert F. (Dec 1939). "Studies in Retention" (PDF). Journal of Educational Psychology 30 (9): 641–656. doi:10.1037/h0063404. ISSN 0022-0663. 
  3. ^ Piotr Woźniak: Theoretical aspects of spaced repetition in learning
  4. ^ Wolf, Gary (2012), "QS Primer: Spaced Repetition and Learning", Quantified Self 
  5. ^ Biedalak K., Murakowski J., Woźniak P.: Using SuperMemo without a computer – Paper and pencil method
  6. ^ Purdy, Kevin (2010), "Use Incremental Reading to Memorize Large Batches of Data", Lifehacker 
  7. ^ Piotr, Woźniak, Early implementations of SuperMemo 
  8. ^ 3. Account of research leading to the SuperMemo method, 3.1. The approximate function of optimal intervals and 3.2. Application of a computer to improve the results obtained in working with the SuperMemo method, P. A. Woźniak, Optimization of learning, Master's Thesis, University of Technology in Poznan, 1990.
  9. ^ What spaced repetition algorithm does Anki use?, "If you are very consistent in your studies and all cards are of a very similar difficulty, this approach can work quite well. However, once inconsistencies are introduced into the equation (cards of varying difficulty, not studying at the same time every day), SM3+ is more prone to incorrect guesses at the next interval – resulting in cards being scheduled too often or too far in the future. "Furthermore, as SM3+ dynamically adjusts the "optimum factors" table, a situation can often arise where answering "hard" on a card can result in a longer interval than answering "easy" would give. The next times are hidden from you in SuperMemo so the user is never aware of this."
  10. ^ [1]

External links[edit]