You can process all elements in a given branch of the knowledge tree or in a browser by means of the subset processing menu. This menu is available as Process browser on the browser menu, or as Process branch on the contents menu. It can also be accessed in the contents window and in the browser with a dedicated menu button on the toolbar (second from the left).

The options of the subset processing menu are listed below. Subset elements should be understood as the elements of a given branch or the elements listed in the browser (depending on the context in which the menu is used: contents or browser). 

• Learning
  • Learn - make outstanding repetitions on elements included in the subset. The sequence of repetitions is determined by how elements are sorted in the subset (i.e. not by the global repetition schedule). Once outstanding repetitions are made, proceed with memorizing subset elements that are listed in the pending queue
  • Review all - review all elements in the subset. Elements that are not outstanding are subject to mid-interval repetition. Mid-interval repetition results in optimally rescheduling the element. If the review interval is much shorter than the optimum interval, the new interval will not be much longer than the preceding interval. If the review interval is close to the optimum interval, the new interval will be nearly as long as if the repetition took place at optimum time. Dismissed elements are not subject to review. Elements that have already been reviewed on this particular day will also be skipped. Use Review all if you urgently need to review a portion of material (e.g. before an exam). You could use Learn before using Review all to make sure you start from the outstanding material (incl. items that are most likely to be forgotten). Alternatively, you could sort the subset by the date of the next repetition (starting from the earliest dates) to maximize subset recall in case you do not manage to complete the entire review
  • Review topics - review topics only. Unlike Review all, this option does not review items. This makes it possible to use it often without a detriment to the learning process. Abusing Review all can result in an increase in total workload and a decrease in retention. In particular, important items may be sent to excessively long interval due to repetition clustering (i.e. similar items serving as answer cues and masking recall problems)
  • Dilute - same as Postpone but with this difference that all elements in the subset will be affected (not only outstanding elements)
  • Spread - reschedule all elements equally in a given period of time (e.g. make sure that all items related to geography are rescheduled in equal portions of 20 items per day in the period of one month). Please note that you might want to first choose Child : Outstanding (see above) to make sure that you reschedule only outstanding repetitions, i.e. not all repetitions in the entire subset. You can also choose Child : Items to make sure you reschedule only item repetitions. For more details see: Mercy
  • Remember - memorize all elements that have not yet been memorized
  • Forget - remove all memorized elements from the learning process and put them at the end of the pending queue
  • Dismiss - dismiss all elements, i.e. ignore them in the learning process
  • Undismiss - return all dismissed elements to the pending queue
  • Done - execute Done on all elements. Upon confirmation, Done will delete the contents of individual elements, dismiss them, and delete the elements that have no children (for more see: incremental reading)
  • Add to drill - add all elements in the subset to the end of the final drill queue
  • Reset history - reset the repetition history of all elements in the subset
• Postpone - increase intervals of all outstanding repetitions in the subset by a selected factor (e.g. 1.02 will increase intervals by 2%)
• Advance - opposite to Postpone. In the case of topics, elements will be rescheduled with new intervals falling into a selected range. For example, if you want to thoroughly review all topics related to whiplash injury over the period of two weeks, search for whiplash (Ctrl+F), choose Advance, and select 14 (number of days in the review period). Advance works differently for items. All items will be rescheduled within the period of the advance interval starting with tomorrow. Unlike in the case of topics, item intervals may still be very long. Just short enough to fall within the review period. For those items that are lucky to retain long intervals, if your recall is good, you will not need to waste time on reviewing them frequently after the review period. The formula for the next repetition date is the same for topics and items: today+[1..Advance Interval]. The formula for the new interval is: [1..AdvanceInterval] for topics and (Today + [1..AdvanceInterval) - LastRepetition) for items.
• Priority - change the priority of elements in the subset
  • Increase - increase the priority of elements in the subset. If you choose the default change of 90%, all priorities will be multiplied by 0.9. For example, elements with priority 70% will have their priority increased to 63% (70%*0.9=63%). Note that in massive changes to priority, elements listed at the beginning of the subset will be modified first. This means that modifications to priority to later elements will affect the priority of elements modified first. Not always will you get the exact increase in priority as indicated by the Change field
  • Decrease - decrease the priority of elements in the subset. If you choose the default change of 110%, all priorities will be multiplied by 1.1. For example, elements with priority 70% will have their priority decreased to 77% (70%*1.1=77%)
  • Spread - spread the priority of elements within a selected range. For example, if you choose a range from 1% to 10%, and the subset has 10 elements, they will roughly receive the priorities of 1%, 2%, 3%, etc. Remember that rounding errors may produce different figures if the collection is small. In addition, in a narrow priority range, elements processed first may be displaced by elements processed later due to rounding errors. If there aren't enough priority positions to spread within the subset, only as many elements will be processed as there are priority positions available
• Forgetting index - change the forgetting index of all elements in the subset
  • Set forgetting index - assign a given forgetting index
  • Default forgetting index - make all elements use the default forgetting index. The default forgetting index is set with Tools : Options : Learning : Forgetting index
• A-Factor - change the A-Factor of all elements in the set:
  • Set A-Factor - set the A-Factor to a selected value
  • Modify A-Factor - multiply A-Factors by a selected number
• Ordinal - change the ordinal number of all elements in the set:
  • Set ordinal - give all elements the same ordinal number
  • Set difficulty ordinal - give all elements ordinals derived from item difficulty (easier items will get lower ordinals). This makes it possible, for example, to sort the pending queue in such a way that easy elements come first in learning
  • Spread ordinals - give all elements ordinals increasing in equal steps from a given lower limit to a given higher limit
  • Blend ordinals - set ordinals by position in the subset weighed against the position in another subset. If you have the same set sorted in two different ways, you can find a sorting order that falls into the middle between these two sorting orders. For example, if you have a collection that has been ordered by the position of elements in individual branches, you can set up a pending queue in such a way that difficult elements are pushed slightly towards the end of the queue. To accomplish this goal, sort the set by difficulty and save it in a subset file. Then sort the set by the original order and blend ordinals with the previously saved difficulty order set. The blend factor will determine how much the current sorting order is modified (0 for no change and 1 for the order from the subset file)
  • Set position ordinal - give all elements ordinal numbers equal to their physical position in the collection (e.g. to sort the pending queue in the order of adding elements into the collection)
  • Set pending ordinal - give all elements ordinal numbers equal to their position in the pending queue
  • Modify ordinal - increase or decrease ordinal numbers of all elements
• Template - template operations (for more details see: Using templates)
  • Apply template - apply a selected template to all elements in a given element subset. Unlike in earlier versions of SuperMemo, this operation is reversible. You can always apply a different template or use Detach template on element menu to remove the applied template from individual items
  • Impose template - execute Impose template operation on all elements in the subset. This will make sure that the source template of all elements is overwritten with the template applied to those elements 
  • Detach template - detach template from all elements in the subset and display their original template-less source data
  • Replace template - replace the template in all elements (see Using templates). This operations is similar to Apply template but it is not reversible, i.e. the source template of all elements will be overwritten
  • Add template - add a template to all elements (see Using templates). You can use this option, for example, to add a specific component to all elements in the subset
  • Insert picture - add a picture illustration to all elements in the subset
• Move
  • To a branch - move the elements to a selected branch in the knowledge tree
  • To a category - move the elements to a selected category
• Type - change the type of topics or items (tasks will not be affected)
  • Make items - convert all topics to items (see also: Topics vs. items)
  • Make topics - convert all items to topics (see also: Topics vs. items)
• Set title - assign a given title to all elements
• Statistics (Ctrl+Shift+B) - collect learning statistics for the elements in the subset. In the example below, a subset of 2455 elements is being analyzed. Some exemplary statistics of interest: the average item intervals is 988 days, the average number of repetitions is 3.9, and the measured forgetting index is slightly higher than the requested forgetting index (this is quite understandable considering a high number of postpones). The forgetting index for the first repetition equals 27% only to drop to 8.4% for most recently executed repetitions. Overall retention is 95% and the total size of texts in the subset is 280 KB.

SUBSET STATISTICS (Jun 19, 2004)
c:\sm2004\systems\all

Elements: 2455
Items: 2423
Topics: 32
Memorized: 2423
Dismissed: 32

Items: 2.36% of all items
Topics: 0.02% of all topics
Memorized: 1.20% of all memorized
Burden: 4.143 elements/day (0.34%)
Item Burden: 4.143 items/day (1.83%)
Topic Burden: 0 topic/day (0%)
Item Repetitions: 3.87
Topic Repetitions: 0
Item Interval: 988.063
Topic Interval: 0
Item A-Factor: 4.923
Topic A-Factor: 1.56
Average item postpones: 5.125
Average topic postpones: 0
Total postpones: 12418 + 0

Requested forgetting index: 9.96%
Measured forgetting index: 10.26%
First repetition f. index: 27.3%
Last repetition f. index: 8.38%
Forgetting index cases: 11313
RETENTION: 94.78%

Item text size: 280.909 KB
Topic text size: 0 bytes
Total text size: 280.909 KB