
  Copyright (c) SuperMemo World 1991
  All Rights Reserved


This file is NOT the manual mentioned in
other SM6 files (README.TXT, OFFER.TXT, etc.)
This file is just a selection of the most 
significant pages from the SM6 help. 

The following topics are covered:

1 Introduction
2 Basic operations in SM6
3 Main screen
4 Browsing mode options
5 Menu options
6 Hot keys
7 SuperMemo databases
8 General principles of SuperMemo
9 Hints and tips for SuperMemo users
10 Error reports
11 Passwords


For a detailed description of terms used here
refer to the SM6 help index (press F6 when in
SM6).




1           INTRODUCTION
=============================================

         SuperMemo 6.0 Professional
     Help File, ver. 1.0, Aug 12, 1991
         (c) SuperMemo World 1991

  Welcome to the world of SuperMemo - your
  gateway to better life, better self-image
  and better future for all of us.
  In the breathtaking days of unprecedented
  growth of our civilization, the individual
  demand for new knowledge and better
  understanding is overwhelming.
  Capabilities of human memory became a
  bottleneck of creative thinking.

To keep pace with new ideas and solutions we
need a revolution in the methodology of
learning. SuperMemo lays ground for such
a revolution.
Given a dose of persistence, you can witness
an amazing boost of your intelectual powers,
memory capacity and knowledge of whatever
you choose to be worth knowing.
This is not a commercial hype. SuperMemo has
been developed on purely scientific basis,
and in strictly scientific terms it can
defend its underlying principles, as well as
to demonstrate its incredible effectiveness.
           Get it working now!

Knowledge that is to be learned by means of
SuperMemo 6 must be represented in a text
form, as a collection of question-answer
pairs, later called items.
A collection of items will later be referred
to as a database.
SuperMemo allows to learn and retain
knowledge represented in the database at the
speed that is close to the maximum natural
capability of human memory.
This is achieved by means of repetition
scheduling, i.e. computing exactly when and
which item should be repeated in order to
produce the maximum memory formation effect.

In spite of what it may seem at first, the
SuperMemo-based learning is straightforward.
There are only two simple operations you
have to learn in order to start:
  1. How to create a database
  2. How to learn and retain the knowledge
To ensure the security of your databases,
you should also learn few facts about
database maintanance.
And that's all! All the rest is optional!

Do not delay. Start working now. You have
much to win.
                       BEST OF GOOD LUCK!






2    BASIC OPERATIONS IN SM6
==========================================


2.1     CREATING A NEW DATABASE
-------------------------------

You do not have to create your own databases.
You can obtain them from your colleagues or
from the SuperMemo World's Database Bank.
To create your own, customized database do
the following:
  1. Initialize the files of your database
     by choosing the Miscells:Initialize
     option (press Alt-I, and provide
     an 8-letter name for the database)
  2. Add new items to your database by
     choosing Expand (press Alt-E)
  3. Close the database (e.g. by Quit).



2.2     EXPANDING THE DATABASE
------------------------------

You can add new items to the database by
means of the Expand option.
Follow the steps:
 1. Select Expand (e.g. by pressing Alt-E)
 2. Type in the question
 3. Press PgDn to get to the answer pane
 4. Type in the answer
 5. Press ESC
 6. If you want to terminate the Expand
    option then press ESC again, otherwise
    go to Step 2
See also: Editor Simplicity



2.3         LEARNING
---------------------------

In order to learn new items and repeat items
that have already been memorized, go through
the Learn option (press Alt-L to start)

REMEMBER: TO MAKE YOUR WORK TRULY EFFECTIVE
  YOU SHOULD PASS THE LEARNING OPTION
  EVERY DAY OR ALMOST EVERY DAY!!!
  It is better to work moderatly in regular
  intervals than to rack one's brain to
  death just from time to time.

See: Advice Optimization


Each day, the learning process is composed
of the following stages:
   1. repeating items scheduled for
      repetition on the current day
   2. learning new items from the database
   3. repeating again items that appeared to
      be most difficult in Steps 1 and 2
Each of these steps is a series of single
repetitions that proceed as follows:
   1. displaying a question
   2. answering the question (verbally or
      mentally)
   3. displaying the answer (for comparison)
   4. inputting the response quality <0..5>

The response quality provided by the learner
after each repetition is intended to tell how
good the response was. The grades/scores are:
    5 - excellent response
    4 - correct response after a hesitation
    3 - correct or slightly distorted
        response produced with an effort
    2 - incorrect response where the correct
        answer seemed obvious
    1 - incorrect response where the correct
        answer can hardly be recalled
    0 - complete blackout
In SuperMemo, you are unlikely to use
response qualities 0 and 1!


2.3.1    REPEATING OUTSTANDING ITEMS

Repetition of outstanding items comes as
the first stage of the Learn procedure.
In this stage, all items scheduled on the
current day, as well as all outstanding
items from days on which repetitions has
not been made, are repeated in turn and
scheduled on other dates (depending on the
corresponding values of optimal intervals).
All items that score below 3 are considered
forgotten, and items that score below 4 are
scheduled for additional repetition on the
same day (Final drill).


2.3.2     MEMORIZING NEW ITEMS

The second stage of the Learn procedure
consists in memorizing new items, and is
passed through only after an explicit
request from the learner.
New items taken from the Intact group are
memorized in the sequence of appending to
the database.
Items that scored below 4 are scheduled for
additional repetition on the same day
(Final drill).


2.3.3        FINAL DRILL

This is the third and the last stage of the
Learn procedure.
Items that scored below four in the two
previous stages, Outstanding/Current and
Memorization, are repeated again and again
until they all score at least four in the
response quality assessment.





3          MAIN SCREEN
============================================


The organization of the main SuperMemo screen
is as follows:
 SuperMemo 6 ͻ
          Options of the main menu         
͹
        Question pane           Process   
͹   pane      
         Answer pane                      
͹             
                                         
   Item pane    Test pane                
                                         
ͼ



3.1      QUESTION AND ANSWER PANES
-----------------------------------

These are the two parts of the main SuperMemo
screen where the question and answer of the
currently processed item are displayed.
If the answer pane is not empty, then
SuperMemo is in the browsing mode (except
for the moment when the response quality is
being input at learning).
In the browsing mode, the item currently
presented in the question and answer panes
may be edited, deleted, duplicated, reset,
printed etc.



3.2            ITEM PANE
--------------------------

The item pane is the part of the SuperMemo
main screen where the information about the
currently processed item is displayed.
The information pertains to the item whose
content is presented in the question and
answer panes, and is as follows:
Number - number of the item
Grade - recently input response quality
  for the item (if any)
Repetition - number of the repetitions the
  item have been subject to, separated by the
  colon from memory lapses (number of times
  the items has been forgotten)

Factor - E-factor characterizing the
  difficulty of the item
Used factor - recent ratio I(n)/I(n-1)
  where I(n) is the current interval of
  the item (for Repetition=1, Used factor
  equals the current interval)
Interval - current interval that separates
  the last and the nearest repetition of
  the item
Last date on which the item has been
  repeated (if any), separated by a hyphen
  from the next date on which the item is
  scheduled for the nearest repetition.



3.3           TEST PANE
------------------------------

The test pane is the part of the SuperMemo
main screen where the information pertaining
to the currently performed repetition is
displayed.
It consists of the following:
RF - old and the newly computed value of
  the retention factor corresponding to the
  relevant E-factor and repetition number
OF - old and the newly computed value of
  the optimal factor (the optimal factor
  matrix is a smoothed equivalent of the
  retention matrix)
OF support - number of repetition instances
  used to compute the RF and OF factors
  displayed above
New factor - newly computed value of the
  E-factor for the repeated item
Opt interval - next optimal interval for the
  repeated item (it equals to the value of
  the previous interval multiplied by the
  relevant entry of the OF matrix)
New interval - next value of the current
  interval computed for the repeated item
  (it equals the optimal interval +/- a
  random deviation)
Next rep - date of the next repetition



3.4         PROCESS PANE
-----------------------------

This is the rightmost part of the main
SuperMemo screen where most important
information about the currently used
database and its optimization process are
displayed.
An empty process pane indicates that no
database is in use.
The information presented in the process
pane is as follows:
Database - name of the database in use
Date of initialization of the database in
  use separated by a hyphen from the current
  date
Day - number of the day of the process (since
  initialization)
Memorized - number of items in the database
  that have already been memorized by means
  of Learn)
Intact - number of items in the database
  that have been added by means of Expand
  and have not yet been memorized
Total - total number of items in the
  database (Total=Memorized+Intact)
Outstanding - number of items that should be
  repeated on the given day separated by a
  colon from items that will be repeated
  again because of response quality below 4
Burden +/- change of the Burden parameter
  in the current session (see below)
Burden - average number of items that are
  repeated per day
Mean time - average time used for repeating
  a single item (in seconds)
Workload - average time used for repetitions
  per day (Workload = Mean time * Burden)
Interval +/- change of the Interval parameter
  in the current session (see below)
Interval - average current interval assigned
  to items in the database
Factor - average E-factor assigned to items
  in the database
Repetition - average repetition number
  assigned to items in the database separated
  by a colon from the average number of
  memory lapses per item
Lapses +/- change of the Lapses parameter in
  the current session (see below)
Lapses - forgetting index recorded in
  repetitions (the number in parentheses
  indicates the requested value of Lapses)
Retention - estimated retention of knowledge
  for the database in use
Grade - average response quality
Time - repetition time for the current
  session




4      BROWSING MODE OPTIONS
==========================================


Browsing mode is the state of the SuperMemo
program in which such database operations as
Edit, Delete, Select, Print, etc. are
available (press E, D, S, P, etc.).
SuperMemo enters the browsing mode in the
following contexts:
 - after each repetition in Learn
 - after finding an item by Find
 - after choosing an item by Select
 - after displaying an item assigned on a
   given day in Burden
 - after each repetition in Random test.

Browsing mode operations are summarized in
the status line and are as follows:
  Edit - edit the currently displayed item
  Delete - delete the currently displayed
    item
  Select - display an item of a given number
    and return to the browsing mode
  Print (^P) - print the currently displayed
    item
  Reset (^R) - reset the currently displayed
    item, i.e. remove it from the set of
    memorized and treat it as an intact,
    not yet memorized item
 Duplicate (^D) - duplicate the currently
   display item, edit the copy and return to
   the browsing mode
 Last (^L) - repeat the last operation of
   substring replacement
 Renew - display the updated information in
   the Item pane (useful during the test to
   inspect the new value of the Used factor)
 Arrows - move one item forward or backward
 PgUp/PgDn - move a couple of items forward
   or backward
 Home/End - move to the first or last item
 Enter - continue (or move one item forward)
 ESC - exit


4.1          EDIT
--------------------

The item editor is called by the following
commands:
 - Expand (adding new items to the database)
 - Edit (in the browsing mode)
 - Duplicate (in the browsing mode).
The editor makes use of the Question and
Answer panes of the main screen.
The following commands are available:
  Arrow keys - move the cursor (only within
    the current pane)
  Ctrl-> - move one word right
  Ctrl<-   move one word left
  Backspace - delete the symbol preceding the
    cursor, and paste lines if the cursor is
    placed in the first column
  Del - delete the symbol at the cursor's
    position, and paste lines if the cursor
    is placed at the end of the line
  PgUp/PgDn - change the current pane
    (from Question to Answer and vice versa)
  Enter - cut the current line and move to
    the beginning of the next line
  Ins - change the mode from Insert (new
    characters are inserted into the text)
    to Overwrite (new characters overwrite
    the old ones)
  Tab - swap the panes
  Home/End - go to the beginning or end of
    the line
  ^Y - delete the current line
  ^T - delete the word to the right of the
    cursor
  ^QY - delete all the characters from the
    cursor's position to the end of the line
  ^S - swap the current line with the next
    one (used for reordering enumerative
    answers)
  ^R or ^QA - replace a string of characters
    with another string
  ^L - repeat the last replace operation
  F7 or ^KB - mark the beginning of a block
  F8 or ^KK - mark the end of the block and
    move the block to the buffer
  ^KC - copy the block stored in the buffer
    to the current cursor's position
  ESC - move to the Answer pane (if in the
    Question pane), or exit the editor (if
    in the Answer pane)
Note that when using Expand, the ESC key
will allow to leave the editor, but Edit
will be reentered in order to allow to input
more items. Therfore, to quit the editor
while using Expand press ESC twice (or three
times if in the Question pane).


4.2         DELETE
---------------------

This operation is available only in the
browsing mode.
It is used to delete the currently displayed
item.
Before deleting is performed, SuperMemo will
ask you to confirm your decision.
Delete preceded by Duplicate may be used to
move the item to the end of the database.



4.3          SELECT
---------------------

This operation of the browsing mode allows
to display the item of a given number.
It may be used whenever any of the SuperMemo
procedures reports a database integrity
error.
In such cases, the number of the defective
item is often displayed, and can be used
with Select to inspect the problem.



4.4           PRINT
---------------------

This operation of the browsing mode should
be used only if a printer is connected to
the computer (LPT1).
Print sends the currently displayed item
to the printer, and can primarily be used
to simplify items in the database.
Inexperienced learners are inclined to
produce monster items which should be
split into many simpler ones.
In case of discovering an item that causes
persistent problems, print it, delete it,
and use the printout for formulating an
equivalent set of simpler and univocal items.


4.5           RESET
--------------------

This operation of the browsing mode allows
to transfer an item from the Memorized to
the Intact category.
In other words, the reset item will be
treated as a new, intact item, and all the
process parameters will be updated
accordingly.
The reset should be used each time an item
has been substantially reformulated.
It can also be used in case of mistakenly
providing a pass grade to a forgotten item
when the new interval is very long.


4.6            DUPLICATE
-------------------------

This operation of the browsing mode allows to
use old items to produce new, similar items.
For example, if the old and the new item
differ by just only one phrase, it is easier
to duplicate the old item, and change the
phrase in the newly created duplicate.
Duplicate acts as follows:
  - make an intact copy of the duplicated
    item (placed at the end of the database)
  - enter the editor to edit the newly
    produced duplicate
  - return to the old item
  - reenter the browsing mode.


4.7           LAST
--------------------

This command of the browsing mode allows
to repeat the last replace operation used by
the item editor.
If no replace operation has been made since
loading SuperMemo, the Last command will
have no effect.
Similarly, it will have no effect if the
replaced string is not a part of the current
item.
In combination with Find, Last is used to
replace a given string of characters
throughout the database.

For example, if you want to replace the
string '(mathematics)' with '(math)'
throughout the database, do the following:
 1. use Find to search for '(mathematics)'
 2. as soon as the first item has been found,
    enter the editing mode (E) and define the
    replacement string by pressing ^R (it
    will replace the string in the current
    item)
 3. exit the editor and press Enter to
    continue the search
 4. if another item has been found, decide
    if you want to replace the string, press
    ^L if yes, press Enter and go to 4


4.8           RENEW
----------------------

This is a specialized option of the browsing
mode used only during repetitions.
It is used to inspect the value of the
U-factor (Factor used), which is:
 - before the Grade is provided: the planned
   value of the U-factor
 - after the Grade is provided: the real
   value of the U-factor (used in
   optimization)
 - after using Renew: the new, planned value
   of the U-factor.







5    MENU OPTIONS
============================================


5.1           OPEN
---------------------

To open a database use Open (F3 or Alt-O).
Open is also automatically called when you
want to use any of the options that need an
open database.
Open selects and prepares a database for use.
It displays a window with the names of all
databases stored in your database directory.
Use arrow keys and Enter to choose the
database you want to work with.
If you want to change the drive or path to
the database directory press TAB to move
between panes of the Open window.
The panes are as follows (clockwise): Files,
Drive, Path and Template.
You can define a database filename template
using wildcard characters ? and *, e.g. if
you have the following database in your
directory (geography and economics: GEOG_A,
GEOG_B, ..., GEOG_N and ECON_A, ECON_B, ...,
ECON_N, you can define the template GEO*.INF
to work only with databases on geography.
Do not change the filename extension in the
template pane.
If no database is listed in the Open window
then either you haven't created any database
or the database path is wrong.


5.2 LEARN AND EXPAND
---------------------

For information about these options see
chapters 2.2 and 2.3 in this file.


5.3         FIND
-----------------

Find is used to search the database for
items containing a defined string of
characters (press Alt-F to call it).
Upon chosing this option, input the string
you want to search for (search string).
As soon as an item has been found, it is
displayed in Question, Answer and Item panes,
and SuperMemo enters the browsing mode.
The most recently used string is stored in
in the SM6.PAR file as soon as you use the
Write parameters option.


5.4         SELECT
-------------------

Select is used to display the most recently
used item (press Alt-S to call Select from
anywhere in the SuperMemo program).
Upon displaying the item, SuperMemo enters
the browsing mode which its operations
available at a keystroke (e.g. Edit, Delete,
Reset, Print etc.).
You can also select an item by its number.
In such a case press Alt-S to get into the
browsing mode and press S again.



5.5          MISCELLS
----------------------

Miscellaneous options of the Miscells menu:
 - Date - setting the DOS date
 - Random test - random presentation of
   items from the database in use
 - Garbage - database garbage collection
   used also to test database integrity
 - Initialize - creation of a new, empty
   SuperMemo database
 - OS Shell - temporary exit to DOS
 - Parameters - menu of SuperMemo parameters
 - Approximate - procedure used to compute
   the OF matrix on the base of the RF matrix
 - Close - closing the database in use.


5.5.1         DATE

The Date option allows to set the current
date used by the SuperMemo program.
The DOS date in your computer will also be
changed accordingly.
The date format depends on the setting of
the Dates parameter in the Parameter menu.
Therefore, it may be DD.MM.YY or MM.DD.YY,
depending on your choice.
The Date option is automatically called if
SuperMemo discovers that the DOS date setting
is much different from what could be expected
from data stored in the database.
REMEMBER TO KEEP THE DATE SETTING ACCURATE!


5.5.2         RANDOM TEST

This option randomly selects items from the
database and presents them by displaying
the question, and after you press a key,
the answer. Press ESC to leave Random test.
You can use Random test to:
 - test your colleagues or students
 - inspect the content of the database
 - compute the participation of particular
   topics in the database
 - check if the proportion of knowledge
   you remember corresponds to the value
   approximated by the Retention parameter


5.5.3            GARBAGE

This option is used to remove superfluous
data from database files.
This process may substantially reduce the
size of some of the files (esp ITM).
As Garbage performs a rough database
integrity checkup, it is recommended that it
be performed once a month or two.
The garbage directory stores temporary work
files (comparable in size to the database).
As Garbage is very read-write intensive,
it should be performed on fast media.
WARNING! Back up your files before garbage
 collection.


5.5.4         INITIALIZE

This option of the Miscells menu allows to
start a new SuperMemo database, and is
activated by pressing Alt-I (or Alt-T:M:I).
It creates a set of four files that are
marked by a unique filename. These files
will store the collection of items and the
information about the learning process.
Initialize asks for the filename, and if it
conflicts with already existing databases,
you will be requested to confirm the decision
to override.


5.5.5        OS SHELL

You can exit SuperMemo temporarily by using
the OS Shell option (Alt-X).
This option loads a new command interpreter,
and allows you to issue commands of the
DOS operating system.
As soon as you wish to return to SuperMemo,
type Exit at the DOS prompt and press Enter.
The database in use is automatically closed
in case your forget returing to SuperMemo.
If your have a number of resident utilities
in memory of your computer, there may be not
enough space for loading COMMAND.COM, and
the 'Out of memory' message will be displayed


5.5.6        PARAMETERS

The Parameters menu is displayed by Alt-P,
and allows to define the following parameters
 Lapses - requested forgetting index, i.e.
   proportion of items that are allowed to
   be forgotten at repetitions (this value
   may vary from 3-20%)
 Paths - directories used by SuperMemo
 Sound - generation of sound signals
 Color - color display
 Dates - date format (DD.MM.YY or MM.DD.YY)
It also allows to Write parameters to the
disk or Read parameters from the disk.


5.5.7        APPROXIMATE

This option of the Miscells menu allows to
reevaluate the current state of the OF matrix
on the base of the RF matrix, and should
be passed through each time the Lapses
option is used to request a new value
of the forgetting index.
The procedure makes use of a hill-climbing
algorithm which is intended to find
parameters of a predetermined function of
optimal factors in order to find the
closest fit to the matrix of retention
factors. This function is then translated
into the matrix of optimal factors.
The predetermined shape of the function of
optimal intervals was established on the
base of results yielded by working with
earlier versions of SuperMemo (particularly
SuperMemo 5).
For the repetition number equal 1, the
function of optimal intervals has a
close-to-linear nature and is approximated
by a procedure akin to linear regression
with the number of repetition instances
considered in the computation.
For the repetition number greater than 1,
the approximation procedure is iterative
in nature.
In this case, the four parameters of the
function of optimal intervals are initially
set to average, expected values, and the
algorithm proceeds toward minimizing the
objective function called the deviation
(sum of square differences between OFs and
RFs).
During iterations, all the parameters are
displayed on the screen, as well as steps
used in the hill-climbing algorithm (akin
to the Rosenbrock method).
The counter variable indicates the number
of steps and iterations of the algorithm as
it progresses.
The progress variable indicates the
decrease of the objective function
(DEVIATION) in particular steps and
iterations, as well as the trailing average
of the iteration progress.
Iterations proceed until the trailing
progress drops below 0.01 or ESC is pressed.
In the former case, the newly computed
parameters of the function of optimal
factors are displayed along the final
value of the objective function.
Selected entries of the RF and OF matrices
are juxtaposed in order to provide ground
for accuracy judgement.
In case the fit is satisfactory, Ctrl-S will
store the newly computed matrix of optimal
factors in the database.
Apart from changing the Lapses parameters,
the Approximation procedure may also be used
in cases where the smoothing scheme seems to
be unsatisfactory and the edge of the matrix
of optimal intervals, displayed by Progress
on the Analysis menu, assumes a jagged,
irregular shape.
WARNING! The approximation algorithm should
only be used after changing the Lapses
paramater, unless the learner truly
understands the optimization procedures.


5.5.8          CLOSE

You can close the database in use by means of
Close (F2 or Alt-C).
Close updates all database files and closes
them.
Close is automatically called by:
  - Quit
  - Open, if you decide to open another
    database
  - OS Shell (to protect your database in
    case you forget returning to SuperMemo)



5.5.9       USER DATA

The User option on the Miscells menu allows
to inspect information about the person,
institution or company that bought the
marked copy of SuperMemo.
This information does not necessarily
pertain to the end user of SuperMemo.
A given copy of SuperMemo may be purchased
for retail sale, and the end buyer becomes
a legal user upon registering his copy
at SuperMemo World.



5.6        ANALYSIS
------------------------

The Analysis options allow to see:
 - Burden - number of items to be repeated
   on particular days
 - Factor distribution - distribution of
   E-factors across the database
 - Interval distribution - distribution of
   current intervals
 - Optimal factors - the OF matrix
 - Support for Optimal factors - matrix of
   repetition cases used to compute OFs
 - Prospects - matrix of optimal intervals
 - Retention - approximation of the OF matrix
   based on sketching forgetting curves


5.6.1          BURDEN

The Burden option can be found in the
Analysis menu (press Alt-B to call it).
It is used to display how many items are
assigned for repetition on particular days
and which these items are.
The following keys can be used when in the
Burden option:
  - arrow keys - move the selection bar
    between days of the current page
  - PgUp/PgDn - present the next/previous
    page of days
  - Ctrl-PgUp/PgDn - move one year forward
    or backward
 - Home - move to the earliest day in the
   process that has not yet been gone through
 - End - move to the furthest day on which
   any repetition is/was scheduled
 - Enter - display the list of items
   scheduled on the day indicated by the
   selection bar (see Assignments)
 - ESC - exit to the Analysis menu

Use the Burden option to see how many items
you have in the schedule for the nearest
days. You are advised not to inspect these
items as it may interfere with repetitions.


             ASSIGNMENTS

You get to the Assignments option by using
Burden (e.g. Alt-B), positioning the
selection bar on a given day and pressing
Enter.
In the right part of the screen, the list
of items scheduled on the selected day is
displayed.
The selection frame can be moved to any of
the items, and the content of the Question,
Answer and Item pane will change accordingly.
The selection frame may be moved by means of
arrow keys, PgUp and PgDn.

Upon moving to the item of interest, most
of the operations of the browsing mode are
available:
  - Edit,
  - Delete,
  - Reset,
  - Print,
  - Select,
  - Duplicate, etc.
By pressing Enter, the browsing mode may be
entered with all its operations at hand.
The browsing mode may be exited by ESC.



5.6.2     FACTOR DISTRIBUTION

This option displays the number of items
belonging to particular difficulty
categories (determined by E-factors).
The range of E-factors is displayed leftmost,
followed by the number of items in each
category, their proportional participation
in the whole database and the histographic
representation of the latter.
A 'flatfoot' distribution with a large number
of 1.3 items is the best indicator of an
ill-structured database, and should be, by
all means, avoided.


5.6.3    INTERVAL DISTRIBUTION

This option presents the distribution of
current intervals attributable to particular
items. The interval category is displayed in
the left column, and is followed by the
number of pertaining items and their
proportional participation in the database.
Initially, soon after creating the database,
intervals are on the order of days, but in
a short time, most of them increase to months
and years. Then, only a small proportion of
items is scheduled in short intervals, and is
accounted for by marginal, but existent
process of forgetting.


5.6.4      OPTIMAL FACTORS

This option displays the matrix of optimal
factors (OF matrix). This matrix is a
tabular representation of the function of
optimal intervals.
Columns are designated by particular
E-factor values, while rows correspond to
repetition numbers (memorization is counted
as the first repetition).
PgUp and PgDn can be used to display lower
and higher half of the matrix, corresponding
to lower and higher E-factors.
See: Optimization


5.6.5     OPTIMAL FACTOR SUPPORT

This option of the Analysis menu allows to
see how many repetition instances have been
used to compute particular entries of the
matrix of optimal factors.
The top row displays E-factor categories
(from 1.3 to 2.5).
The leftmost column displays repetition nos
(from 1 to 20).
The parameter displayed right to the
window header is the number of instances
used to compute the Lapses parameter (FI
stands for Forgetting index)


5.6.6       PROSPECTS

This option allows to see the approximate
values of optimal intervals used in the
process of learning.
In the top row, E-factor categories are
displayed (from 1.3 to 2.5).
The leftmost column displays repetition nos
(from 1 to 20).
Use PgUp/PgDn to inspect both halves of the
matrix (E-factors equal up to 3.2).
First optimal interval in a given E-factor
category equals the first optimal factor for
the same category.

All subsequent optimal intervals are
computed by multiplying the preceeding value
of optimal interval by the corresponding
value of optimal factor:
   OI(1,EF)=OF(1,EF)
   OI(n,EF)=OI(n-1,EF)*OF(n,EF)
where:
   OF(n,EF) is the n-th optimal factor for
     E-factor equal EF
   OI(n,EF) is the n-th optimal interval for
     E-factor equal EF
Intervals longer than the average human
lifespan are not displayed.
(M stands for months, Y stands for years)


5.6.7          RETENTIONS

This option allows to see the content of
the matrix of retention factors.
Retention factors correspond to O-factors,
but their values are computed directly from
forgetting curves sketched for particular
E-factor categories and repetition numbers.
Retention factor expresses the optimal
interval (first repetition) or the increase
of the optimal interval (further repetitions)
for which the expected value of the
forgetting index equals the desired value of
Lapses set by the Lapses option.

For example, if the Lapses parameter equals
5% and the repetition number is one, then
the corresponding retention factor will equal
the interval for which the forgetting curve
indicates the expected 5% of memory lapses.
Because the forgetting curve sketching is
subject to high degree of noise, the
retention factor matrix undergoes smoothing
before it can be treated as the matrix of
optimal intervals. The smoothed form of the
matrix of optimal intervals may be inspected
by means of the Optimal factors option.
You can use arrow keys, Home and End to move
across the matrix of retention factors.

You can see the current state of the
forgetting curve corresponding to a given
retention factor by pressing Enter, while in
the Retentions option (Alt-R).
If you have a color display, you may see that
the color of retention factor entries changes
along with the increasing number of
repetition instances uses to sketch the curve
Obviously, you may wish to inspect only those
entries whose color intensity indicates that
the forgetting curve sketching is in an
advanced stage.

See: Optimization

          FORGETTING CURVES
You can view forgetting curves by using
Retention (Alt-R), positioning the cursor
on a selected entry of the matrix of
retention factors and pressing Enter.
The top row of the forgetting curve window
indicates the values of the R/U-factor
(equivalent to the interrepetitory interval
if the repetition number is 1).
The bottom row of the window displays the
number of repetition instances used to
sketch a given section of the curve.
The vertical axis corresponds to the
forgetting index (top-0%, bottom-100%).
The broken lines that cross inside the
forgetting curve panel indicate:
  - horizontal - desired value of the
    forgetting index (top corresponds to 0%)
  - vertical - Retention factor (factor for
    which the forgetting curve crosses the
    line of the desired forgetting index)
Texture of rectangles used to plot the curve
reflects the number of instances used to
compute the retention for that part of the
graph: the more solid the rectangle, the
greater the number of instances, and in
consequence, the greater the accuracy of
plotting.


5.6.8     MONTHLY BURDEN

This option allows to see how many items are
scheduled for repetition in particular months
and years (press PgUp/PgDn to see the next
or previous panel of four years).



5.7         HELP MENU
-----------------------

Help menu provides the following options:
 - Front page - process help starting from
   its front page
 - Index - process help starting from the
   index which lists all the most important
   topics
 - Recent page - process help starting from
   that page that has recently been used
 - Help on Help - process help starting from
   the page that provides instructions on
   how to use help
 - Hints and Tips - process help starting
   from the Hints-and-Tips page


5.8          QUIT
---------------------

This option of the main menu should always
be used to terminate the work with SuperMemo.
To terminate press Alt-Q, and confirm the
termination by pressing Y(es).

Quit closes the currently used database (if
any), restores the video attributes from
before running the program and disposes
memory area occupied by SuperMemo.







6          HOT KEYS
=========================================

The following hot keys may be used in most
of contexts of SuperMemo:
 F1 - context-sensitive help
 F2 - Close the database in use
 F3 - Open a database
 F4 - recent page of help
 F5 - front page of help
 F6 - help's index
 F10 - main menu
 Alt-O - Open a database
 Alt-L - Learn
 Alt-F - Find
 Alt-S - Select
 Alt-E - Expand
 Alt-D - change Date
 Alt-B - daily Burden
 Alt-M - Monthly burden
 Alt-C - Close the database in use
 Alt-T - Top options (main menu)
 Alt-P - Parameters
 Alt-X - eXit to DOS (OS Shell)
 Alt-H - Help menu
 Alt-Q - Quit



7    SUPER-MEMO DATABASES
============================================


7.1       DATABASE FILES
---------------------------

The following files make up a SuperMemo
database:
<name>.INF - info about the process
<name>.ITM - text of items
<name>.ITI - info about items
<name>.DAT - list of pointers to lists
  storing items scheduled on particular days

Optionally:
<name>.REP - list of items scheduled for the
Final drill (this file can always be erased).



7.2   DATABASE SECURITY PRINCIPLES
----------------------------------

Upon loosing your database files, you are
doomed to forget 60-100% of your knowledge
in the first year depending on how long you
have been using SuperMemo.
To make sure its is not the case, please
do obey all the database security principles
listed on the next page.
Recently, computer viruses have become a
scourge of hard working and honest computer
users. SuperMemo databases are particularly
sensitive as they store highly complex data
produced by months of strenuous work of a
SuperMemo learner. YOU CANNOT BE TOO CAREFUL!

Security principles:
 - always leave SuperMemo by Quit
 - keep your passwords handy
 - in case of abandoning the program in a
   prohibited way (e.g. power failure), use
   your backup copy
 - do not modify database files manually
 - keep a month and two months old database
   backups on diskettes
 - create a temporary backup each time you
   work with SuperMemo (e.g. use RAMdisk)
 - perform Garbage collection once a month
 - do not create databases greater than
   300 kB or 3000 items
 - keep the DOS date setting accurate
 - upon DATABASE INTEGRITY ERROR message,
   backup your database (do not override
   older backups) and perform  Garbage
   collection
 - do not work with databases that report
   integrity errors, use your backups
 - recover from any damage only be means of
   tools provided by SuperMemo World
 - in case of a serious damage, send your
   database to SuperMemo World for recovery
   (remember to attach postage and the
   processing fee as indicated in files
   accompanying SuperMemo)







8   GENERAL PRINCIPLES OF SUPER-MEMO
=============================================

All forms of learning produce molecular
changes in neuronal synapses which form
connections between nerve cells.
These changes are gradually obliterated in
the process of spontaneous forgetting.
Forgetting affects all synapses able to learn
and can be naturally prevented only by one
mechanism: repetition.
Every attentive learner knows, that
forgetting can ruin the delicate fabric of
knowledge that may take months and years to
build.

The saying 'Repetitio est matter studiorum'
is as old as the art of learning.
Not everybody, however, realizes the fact
that: IT IS NOT POSSIBLE TO LEARN ANYTHING
ONCE AND REMEMBER IT FOREVER!
Even one's own name could be forgotten if it
were not used, or in other words repeated,
as often as it is.
The problem with repetitions is that they
consume one of the most valuable assets in
the modern lifestyle: time.
Therefore the key to effective learning is
to find ways to reduce the number of
otherwise ineluctable repetitions.

SuperMemo makes learning approach the
maximum natural capacity of the human brain
to form memories.
This is done by the optimization of
repetition scheduling, i.e. finding out when
and which portions of knowlege should be
repeated.
Considering a given piece of knowledge,
there are two criteria that can be used to
determine the length of optimal intervals
that should separate repetitions:
 - minimization of the number of repetitions
 - maximization of the overall knowledge
   retention.

In other words:
 - intervals should be as long as possible to
   reduce time necessary for repetitions
 - intervals should be short enough to make
   sure that the repeated knowledge is not
   forgotten.
Because of the fact that forgetting has a
stochastic nature, i.e. it cannot be easily
predicted when a given piece of knowledge
will be forgotten, the statistical approach
to the process of learning must be applied.
By means of statistical analysis, we can
determine when a given proportion of
memorized knowledge will be forgotten.

Thus, the following definition of optimal

intervals could be accepted:
OPTIMAL INTERVALS ARE INTERVALS THAT RESULT
IN A SMALL, PREVIOUSLY DETERMINED FRACTION
OF KNOWLEDGE BEING FORGOTTEN.
The mentioned fraction of knowledge, later
called the forgetting index, may be chosen
by the learner, and usually falls into the
range from 5% to 10%.
By application of optimal intervals in the
process of learning, the SuperMemo method
produces an incredible increase in the rate
of knowledge acquisition without affecting
knowledge retention.

A little problem arises when we observe that
optimal intervals differ between different
sorts of knowledge and different learners.
The former problem is dealt with in the
SuperMemo method by splitting knowledge
into smalles possible pieces called items.
The optimization procedure, i.e. computation
of optimal intervals, is then applied to
each of the pieces separately, producing
a unique repetition intervalization in each
of the cases.
The principle of applying items of maximum
simplicity is later called the minimum
information principle.

The problem of differences between learners
is solved in SuperMemo by application of
self-modifying algorithms that adjust
repetition intervalization to individual
needs.
In other words, the procedures used by the
SuperMemo program can detect what sort of
learning and what sort of learner are subject
to optimization.
The net result is that a determined level
of knowledge retention may be maintained in
the process of learning that approaches the
maximum natural speed with which the
learner's brain can form memories.

This is an outline of how SuperMemo allows to
learn fast:
 - the learned knowledge is split into
   smallest possible pieces called items
 - items are formulated in the question-
   answer form
 - items are memorized by answering questions
   as long as it takes to provide correct
   answers to all of them
 - first repetition is scheduled at the same
   time for all items, after the interval
   which statistically produces FI lapses
   of memory (FI stands for the forgetting
   index and equals 5% be default)
 - the first interval is computed as for an
   average learner, but as soon as the FI
   deviates from the requested value, the
   length of the first interval is modified
 - after each repetition, learner produces
   a number called the response quality
   which determines how difficult it was to
   answer the question
 - on the base of response qualities, items
   are classified into difficulty categories,
   and their difficulty is reestimated in all
   successive repetitions
 - different optimal intervals are applied to
   items of different difficulty
 - different intervals are applied to items
   that have been repeated a different number
   of times
 - the function of optimal intervals is
   constantly modified in order to produce
   exactly FI memory lapses
 - the function of optimal intervals is
   represented as the matrix of optimal
   factors OF:
     I(1,EF)=OF(1,EF)
     I(n,EF)=I(n-1,EF)*OF(n,EF)
   where:
   I(n,EF) - n-th interval for difficulty EF
   OF(n,EF) - n-th O-factor for difficulty EF
 - matrix of optimal factors is produced
   by smoothing the matrix of retention
   factors RF
 - each entry of the RF matrix equals the
   current estimation of the optimal factor
   OF that produces FI lapses of memory
 - RFs are computed from forgetting curves
   sketched on the base of repetitions
 - each difficulty category and repetition
   number has its own record of repetitions
   in the form of a forgetting curve sketch
 - intervals used in learning are slightly
   dispersed round the optimal values for the
   accuracy of the forgetting curve sketching









9   HINTS AND TIPS FOR SUPER-MEMO USERS
==========================================

To be truly satisfied with your SuperMemo
workouts, you should obey the following
principles of a successful learner:
 - regular work
 - formulation of simple and univocal items
 - moderation
 - concentration
 - proper selection of material
 - multifaceted approach
 - application of mnemonic techniques
 - health
 - pleasure
 - knowledge of the above principles.


9.1       REGULAR WORK
-------------------------

There is no way of avoiding the fundamental
principle of SuperMemo: REGULAR WORK.
It is better to work 3 minutes every day,
than to spend an hour on weekends.
Regular work may be against the human nature,
it may be hard to bear for some, but the
mechanisms of memory are ruthless, and do not
provide any escape from regular brain-racking
Moreover, the positive feedback between
the pile-up of outstanding repetitions and
the urge to procrastinate is the main source
of SuperMemo casualties.   DO NOT POSTPONE!


9.2  SIMPLICITY AND UNIVOCALITY OF ITEMS
----------------------------------------

One of the main ways to increase the speed
of learning with SuperMemo is to consequently
formulate items that contain minimum
information and are unambiguous.
Minimum information does not mean minimum
number of items. An ill-structured item may
often be replaced by a dozen of simple items,
and the resulting redundancy is likely to
greatly reduce the learning time!
One should never learn convoluted formulas,
lists containing more than 3-5 elements,
sets containing more than 2-3 elements,
descriptions, etc.

All of them should be replaced by a set of
simpler items.
The notable exception are short epigrams,
however, their use may be constrained by the
SuperMemo's limit on the size of an item.
Most of SuperMemo beginners display the lack
of sense of item simplicity. Despite all
warnings, they formulate monster items that
by no means can be reproduced at repetitions.
Usually, the learner will have to learn the
hard way that there are different knowledge
representation strategies that may render
the same piece of knowledge a pushover in
one case, and a nightmare in another.


9.3       MODERATION
----------------------

A dangerous snag awaits all inexperienced
SuperMemo learners as a result of two
phenomena:
 - it is easier to memorize items than to
   retain them in memory over a longer time
 - in the first year of work, the learning
   rate will gradually be reduced as a result
   of accumulation of items scheduled for
   repetitions.
In consequence, the learner, bedazzled with
the initial progress, may overestimate his or
her ability to sustain the working regime.

Soon, he or she will be overwhelmed by the
number of repetition, and the crisis may be
amplified by the increasing difficulty to
recall the ill-structured items.
One of the first things a SuperMemo learner
must do is to test his capability to work
with SuperMemo over a longer period of time.
The best daily dose for beginners is 5-10 min
Only after a month or so, it could gradually
be increased to 30-40 minutes per day.
It is worth noting that the decrease in the
speed of learning becomes practically
undetectable as soon as after the first year
of the process.


9.4       CONCENTRATION
-----------------------

It is important for the quality of knowledge
obtained by means of SuperMemo, that
repetitions are conscious and semantic, i.e.
they do not just reproduce the answers
automatically, without truly grasping all
their implications.
Automatic repetitions not only reduce the
value of the knowledge. They also make the
work with SuperMemo monotonous, and are less
engaging for memory. In consequence, the
repeated items are more difficult to recall.
A truly successful SuperMemo learner finds a
challenge in each repetition.


9.5      SELECTION OF MATERIAL
------------------------------

One of the most important prerequisites of
a success with SuperMemo is the proper
selection of the learned material.
The art is not to know thousands of facts,
but to know just those of them that can be
directly applied in the day-to-day activities
of the learner.
Memorizing a phone number of a colleague may
produce more profit than knowledge of a
sophisticated mathematical formula.
A simple rule for drug application may be
of greater use than a hundred of drug
dosages.

The question:
 'What do I want to learn and why?'
should be a commonplace in the SuperMemo
learner's daily schedule.
SuperMemo allows to learn fast, and therefore
may easily lead somebody to learn a lot of
useless garbage without ever stopping to
ask WHAT FOR?
Applicability must be the primary criterion
in choosing new items to learn.
Applicable knowledge may be a source of
hugely increased effectiveness and personal
satisfaction for the learner.
Garbage items only soak up learner's time.


9.6     MULTIFACETED APPROACH
-----------------------------

It can easily be seen that a dose of smart
redundancy can greatly reduce the learning
workload, and improve the knowledge quality.
Imagine that you want to learn the following
piece of knowledge:
'The cost of smoking to the world's economy
 is $100 billion, while the antismoking
 campain fund is $10 million'
The best way of learning the above facts is
to produce a set of items, that ask for all
the most important aspects and implications
of the learned knowledge.

It may appear sufficient to ask two questions
about the losses produced by smoking and
the cost of the antismoking campain.
However, an important implication may soon be
lost from the learner's memory:
'What is the mutual cost relation of the
 disease and the remedy?'
Answer: 10,000 !!!
Not only implications may be lost.
A learner able to tell what disease is caused
by HIV, may not be able to answer the
question what virus causes AIDS.
Mutlifaceted questions increase the quality
of knowledge and reduce the learning time!


9.8       MNEMONIC TECHNIQUES
------------------------------

One of the principles of SuperMemo is to
formulate simple and univocal items.
However, even the simplest item may be quite
hard to remember.
Numbers are a good example of intractable
polluters of SuperMemo databases.
The problem with numbers is that they are
all similar to each other and can easily be
confused.
Here, the help comes from techniques which
are as old as the art of learning itself:
the mnemonic techniques.

Any good mathematician may demonstrate that
remembering numbers is much less of a problem
to him than to an average man in the street.
Having had to learn hundreds of constants
and formulas, a mathematician more or less
consciously knows how to deal with them.
The simplest technique is the learn a list
of 10, 20 or 100 pictures associated with
numbers. For example: 1 - harpoon, 2 - coin,
3 - tripod, 4 - dog, 5 - hand, etc.
Knowing such associations, numbers may easily
be represented as colorful pictures.
For example: 4315 may be seen as a dog on a
tripod harpooning somebody's hand.

Despite what may seem at first, time spent
on forming the pictures is incomparabe with
gains produced by successful memorization.
By virtue of the brain circuitry developed
in the course of evolution, vivid pictures
are by far easier to retain in memory than
dry numbers.
In SuperMemo, it is always better to
invest heavily in formulation of items, in
order to have only a couple repetitions in
the lifetime.
Ill-structured or intractable items may be
repeated as many as 30 times in the course
of a single year!!!


9.9        HEALTH
--------------------

Health is an obvious prerequisite of success
in any form of learning.
Here, only the greatest natural allies of
SuperMemo are signalled:
 - sleep - nothing can ruin a SuperMemo
   session as effectively as drowsiness
 - physical exercise - jogging and swimming
   have salubrious neutrotrophic effects
   when accompanied by mental effort
 - oxygen - without fresh air, a SuperMemo
   learner will experience signs of extreme
   exhaustion as soon as in the first 5 min
 - abstinence from smoking and drinking.


9.10      PLEASURE
---------------------

The most sure way of telling if all the
principles of effective work with SuperMemo
are satisfied is user's pleasure experienced
during repetitions.
This is an infallible litmus test and should
constantly be examined in order to detect
the causes of unsatisfactory progress.
All problems mentioned earlier such as
backlog of items, recall problems, monotonous
repetitions, garbage knowledge, superficial
items, tiredness, etc. are certain to take
the gilt off the SuperMemo work and result
in disillusionment.       MAKE IT FUN!


9.11    KNOWLEDGE OF THE PRINCIPLES
-----------------------------------

Each of the ten principles of the effective
work with SuperMemo is of a huge importance
on its own.
The problem is that there are nine of them,
and none is less important than the others.
Why not to make use of SuperMemo now, and
learn the principles to make them available
whenever you wish to recall them.
By obeying the principles, you may increase
your effectiveness manifold. Perhaps, the
gain may be as big as from applying SuperMemo
in the first place.
Be on your guard, the reserves are immense.







10     ERROR REPORTS
===========================================


10.1    INTEGRITY ERROR
------------------------

If SuperMemo displays the message:
       'Database integrity error!'
you should not continue working with your
database as it must have been damaged.
Use your backup copies to see if the
problem reappears there.
If you don't have a backup that reports no
errors then you may try to go through
Garbage collection (make a backup copy
beforehand), and see if it could help to
remedy the problem.

If the Garbage collection procedure does not
work, then you may try to use database
recovery tools provided by SuperMemo World.
Unless you are an experienced programmer,
and you fully understand the structure of
SuperMemo databases, any attempt to correct
the damage manually or programmatically
may cause further loss of data!
If you appear to be unable to solve your
problem then consult your dealer, or
send your damaged database to SuperMemo
World (add postage and the processing fee
as indicated in the files accompanying
SuperMemo 6 on the distribution disks).


10.2     OUT OF MEMORY
-----------------------

If SuperMemo displays the 'Out of memory'
message, you should quit the program and
remove some of your resident utilities.
A frequent reason for running out of memory
is just a failure to remember that SuperMemo
has already been loaded, and could be
reactivated by typing Exit (after using the
OS Shell option).
The typical symptom of memory deficit is
unability to restore the content of windows
used by the program.


10.3       CANNOT OPEN ...
--------------------------

The two most frequent reasons of the
'CANNOT OPEN ...' message are:
 - the CONFIG.SYS file indicates a too
   little number of files allowed to open
   (add FILES=20 line to CONFIG.SYS)
 - some of the database files are missing
   from the database directory (note that
   the COPY command of DOS fails to copy
   files whose size is zero)
You may also be unable to open a database
because of a wrong format.


10.4    WRONG DATABASE FORMAT
-----------------------------

This error appears whenever you attempt to
open a database that was created by a
copy of SuperMemo marked by a different
registration number.
To convert a database to another format you
will have to send it to SuperMemo World
for conversion.
Upon your permission, the database will be
added to the Database Bank and distributed
worldwide with 50% of net profit coming back
to you.


10.5     UNCLOSED DATABASE
--------------------------

In case a database has not been closed for
any reason, SuperMemo will display a
warning message.
In such a case, you should use your backup
copy, as the unclosed database might have
lost its integrity.
In case you don't have a backup, try to
run the Garbage collection procedure for
a rough integrity check-up (make a backup
beforehand).
If Garbage reports no integrity errors, you
stand a 3:4 chance that your database is OK.










11        PASSWORDS
===========================================

In order to protect SuperMemo from piracy,
SuperMemo World introduced the system of
password checking.
Every month, SuperMemo will ask the learner
to input the relevant password.
This password is unique for different
learners (different registration numbers)
and for different months.
Each user is periodically sent a collection
of passwords for the coming months, to make
sure that illegal copying is slowed down.

Because the password is asked for each of
the databases, it is recommended that the
password be saved in the parameter set as
soon as the check-up procedure is over.
This will make sure, that in case of all the
remaining databases, all you will have to
do is to press Enter.
To save the password press Alt-P (Parameters)
and W (Write parameters). You may also need
to press Y to confirm overwriting the
parameter file (if it exists).
Remember to have your passwords handy each
time your work with SuperMemo (e.g. keep the
passwords in the SuperMemo backup sleeves).

On no condition should you reset or turn off
the computer at the moment of a password
check.
This evasive action is likely to cause a
damage to your database (consequences
depend on the context of the check-up).
SUPER-MEMO WORLD TAKES NO RESPONSIBILITY
FOR ANY DAMAGE THAT MIGHT RESULT FROM THE
USER BEING UNABLE TO PRODUCE THE PASSWORD
AT THE CHECK-UP TIME.

SuperMemo World appologizes for any
inconvenience caused by application of
password checking procedures.
