The option View : Special :
Leeches can be used to locate all elements that cause problems in the learning
process. This option makes use of the element filter dialog box
that can be used to find all element meeting a specific set of criteria such as the number
of repetitions, number of memory lapses, length of the current
interval, status (memorized, pending, or dismissed), type (item
or topic), etc.
The purpose of locating leeches
is to reedit most intractable items with a view to applying appropriate mnemonic techniques. Alternatively you can reset elements
(e.g. to deal with them later), dismiss them (to use them only as reference, e.g. with
Search : Find elements), or simply delete them.
To maximize the effectiveness of the learning process, you should learn to use View : Leeches and periodically remove from your collection most intractable and badly structured material
The following fields can be used to select the minimum and
the maximum values that fall into the range defined for difficult elements:
- Repetitions - number of repetitions made
with a given element. This is not a good criterion for defining leeches and it turned off
- Lapses - number of times a given element
was forgotten. This is the primary field for defining leeches. For example, if you want to
find all elements that have been forgotten at least 5 times, set Minimum
at five and Maximum at 100 (or other value that is greater than maximum
number of lapses)
- Interval - number of days between the last
repetition and the next repetition. You might want to limit intervals to some value (e.g.
1 to 50 days) to account for the fact that even elements that have been forgotten many
times may be disregarded as leeches if they had passed a certain length of interval
without being forgotten
- Last repetition - number of days between
the first day of the learning process and the last repetition date (see Tools : Workload to view day numbering). This field should
not be used in searching for leeches
- Next repetition - number of days between
the first day of the learning process and the next repetition date. This field should not
be used in searching for leeches
- A-Factor - value of A-Factor assigned to a given element. This is not a good
criterion for defining leeches. If you want to use if, choose the lower range of A-factors
(e.g. from 1.3 to 1.5)
- Forgetting index - probability of
forgetting a given element during each repetition. The forgetting index is set by the user
and is by no means a reflection of element difficulty. You might use it however to locate
items of lower priority (e.g. as defined by a higher forgetting index). By using the
forgetting index field you might sharpen the leech criteria for elements that are of lower
priority. For example, you might decide to reset all leeches and be more strict with
resetting elements to which you assigned a higher forgetting index
- Ordinal number - ordinal number assigned to a given element. The ordinal
number is set by the user and is by no means a reflection of element difficulty. You might
use it however to locate items of lower priority (e.g. as defined by a higher ordinal
numbers). This way you might sharpen the leech criteria for elements that are of lower
If you do not want to use a given criterion, uncheck the
check-box associated with a given field. If you do want to use it, check the check-box and
specify appropriate minimum and maximum values.
The fields Type, Status, Item, Topic
and Memorized should not be used in searching for leeches. By definition,
all leeches are memorized items.
Once you click OK, all leeches meeting the
specified criteria will be found and will be displayed in a browser.
Leech parameters are stored between sessions in the file <supermemo directory>\<systems>\<collection
name>\ks.ini in the section [Leech].