Theory

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To study your memory and sleep, use options available in SuperMemo in the following places:

Examples

Tools : Workload

You can use Tools : Workload (Ctrl+W) to inspect the daily and the monthly calendar of repetitions. You can view the number of repetitions scheduled, number of scheduled topics, number of scheduled items, as well as the record of past repetitions, and past retention, or how many new items were memorized.

Daily workload

SuperMemo: Tools : Workload : Daily tab showing the record of repetitions executed over a three-month period

Monthly workload

SuperMemo: Tools : Workload : Monthly tab showing the record of repetitions executed over a three-year period

Tools : Statistics : Analysis

You can use Tools : Statistics : Analysis (Shift+Alt+A) to inspect your forgetting curve, daily changes to your measured forgetting index, your learning overload, and many more:

Forgetting curve

SuperMemo: Tools : Statistics : Analysis : Forgetting Curves graphs for 20 repetition number categories multiplied by 20 A-Factor categories

Daily changes to the measured forgetting index

SuperMemo: Tools : Statistics : Analysis : Use : Efficiency : Forgetting index shows you the changes to the measured forgetting index on individual days

Priorities missed due to overload

SuperMemo: Tools : Statistics : Analysis : Use : Priority protection : Topics shows your actual processing capacity for high-priority topics on individual days

Tools : Statistics : Statistics

You can use Tools : Statistics : Statistics to supervise and understand your learning process:

Tools : Statistics : Element data

You can use Tools : Statistics : Element data to inspect learning statistics of a given element:

Element menu : Learning : Show repetition history

You can use Learning : Statistics : Show repetition history (Shift+Ctrl+H) (on the element menu) to inspect the history of repetitions for individual elements:

SuperMemo: Repetition history dialog box displaying the history of repetitions for the current element

Figure: Repetition history dialog box displaying the history of repetitions for the current element related to the Malpighian body and the renal tubules. In this example, the item has been repeated 11 times thus far. It was forgotten only once at the 3rd repetition on Apr 20, 1999 (after 97 days since the previous repetition). Since then it has been recalled successfully every time. It was last repeated on Aug 31, 2023 at 15:48:45. The hour data is present only for the last two repetitions due to the fact that SuperMemo registers the repetition hour only as of SuperMemo 13 onwards (hours are used in correlating retention with sleep data available from SleepChart). The item is scheduled for repetition in roughly 4 years (on Sep 02, 2027)

Repetitions graph

Repetitions graph for any subsets of elements can be shown in the browser with Tools : Repetitions graph on the browser menu:

SuperMemo: Time flow of knowledge in the learning process

Figure: The horizontal axis corresponds with the repetition number and the vertical axis represents intervals (logarithmic scale). Despite a popular belief, the semi-log scale does not produce a linear graph here. Clearly the increase in the length of intervals slows down with successive repetitions. Moreover, the graph corresponding with zero lapses (red curve), results from the superposition of items with lower and faster increase in intervals (determined by difficulty). The bell-shaped curve is determined by all contributing items (below repetition number 10) and then only by difficult items or items with low forgetting index for which the increase in the length of intervals is significantly slower (above repetition 10). To see the above graph in your own collection, use Tools : Repetitions graph on the browser menu

Tools : Sleep Chart

You can use Tools : Sleep Chart (F12) to optimize the timing of your sleep as well as the timing of your learning:

Sleep and repetitions timeline

Inspect the timeline of repetitions and sleep:

SuperMemo: SuperMemo: Sleep and repetitions timeline displaying repetitions blocks of the current collection (in red) and sleep blocks (in blue)

Figure: Sleep and learning timeline. Sleep blocks are marked in blue. Learning blocks in red. Total learning time on individual days is displayed on the right. The currently selected sleep block turns yellow. Its length is displayed at the bottom. A sleep block whose color bleeds from blue into pink denotes interrupted sleep (e.g. with an alarm clock). A sleep block with the color changing from black to blue marks a delayed sleep episode (e.g. caused by watching a late tennis match).

Look for the best time for learning or sleep (see Sleep Chart for details):

SuperMemo: Sleep and repetitions timeline displaying repetitions blocks of the current collection (in red) and sleep blocks (in blue) with recomputed circadian approximations on the current data

Figure: Sleep and repetitions timeline displaying repetitions blocks of the current collection (in red) and sleep blocks (in blue) with recomputed circadian approximations on the current data. Blue and red continuous lines are predictions of optimum sleep time using the SleepChart model (based on sleep statistics). Yellow continuous line shows the prediction of the maximum of circadian sleepiness (circadian middle-of-the-night peak) using a phase response curve model. Note that, theoretically, the yellow line should roughly fall into the middle between blue and red lines. However, when a disruption of the sleep pattern is severe, those lines might diverge testifying to the fact that it is very hard to build models that fully match the chaotic behavior of the sleep control system subjected to a major perturbation. Aqua dots point to the predicted daytime dip in alertness (i.e. the time when a nap might be most productive).

Alertness

See how your brain gradually loses its power during the day:

SuperMemo: Tools : Sleep Chart : Alertness (H) graph makes it possible for you to visually inspect how grades decrease during the waking day

Figure: Toolkit : Sleep Chart : Alertness (H) graph makes it possible for you to visually inspect how recall (and grades) decrease during the waking day. It also shows the impact of circadian factors with grades slightly lower immediately after waking and slightly higher after the mid-day dip in the 9th hour. The blue dots are recall data illustrating decline in performance during a waking day from 87.5% at waking to 81.5% at midday nadir (size of the circles corresponds with the number of repetitions collected, where minimum 50 repetitions are needed to paint a circle in this particular graph). The yellow line is the estimated homeostatic alertness derived from the sleep log data. The aqua line represents the circadian alertness estimate derived from the same sleep log data. Recall is a resultant of the impact of both sleep-drive processes: homeostatic (yellow) and circadian (aqua). 0.1 (hours) (at the bottom) is the minimum sleep block length taken into consideration. 101,230 repetitions cases were taken to plot the graph. The Deviation parameter displayed at the top tells you how well the chosen approximation curve fits the data (in the picture: negatively exponential recall curve). The lesser the deviation, the better the fit. The deviation is computed as a square root of the average of squared differences (as used in the method of least squares). Depressed Use R will use grade-R correlations for an average student to estimate recall (R derived from the DSR model is not used here, as on the Alertness (C) tab, due to the slowness of the computation). Those correlated R figures may differ from actual recall

Two-component sleep model

Look for the time of the day that should give you maximum learning power (Shift+click a day in the sleep timeline). See when your learning is not likely to be effective and when you should rather go to sleep:

SuperMemo: The predictions of the two-component sleep model about the homeostatic and circadian status of your alertness