<s>
SuperMemo	B-Application
(	O
from	O
"	O
Super	O
Memory	O
"	O
)	O
is	O
a	O
learning	O
method	O
and	O
software	O
package	O
developed	O
by	O
SuperMemo	B-Application
World	O
and	O
SuperMemo	B-Application
R&D	O
with	O
Piotr	O
Woźniak	O
in	O
Poland	O
from	O
1985	O
to	O
the	O
present	O
.	O
</s>
<s>
The	O
method	O
is	O
available	O
as	O
a	O
computer	O
program	O
for	O
Windows	B-Application
,	O
Windows	B-Operating_System
CE	I-Operating_System
,	O
Windows	B-Operating_System
Mobile	I-Operating_System
,	O
(	O
Pocket	B-Device
PC	I-Device
)	O
,	O
Palm	B-Operating_System
OS	I-Operating_System
(	O
PalmPilot	B-Device
)	O
,	O
etc	O
.	O
</s>
<s>
Course	O
software	O
by	O
the	O
same	O
company	O
(	O
SuperMemo	B-Application
World	O
)	O
can	O
also	O
be	O
used	O
in	O
a	O
web	B-Application
browser	I-Application
or	O
even	O
without	O
a	O
computer	O
.	O
</s>
<s>
The	O
desktop	O
version	O
of	O
SuperMemo	B-Application
(	O
since	O
v	O
.	O
2002	O
)	O
supports	O
incremental	O
reading	O
,	O
as	O
well	O
as	O
traditional	O
creation	O
of	O
question	O
and	O
answer	O
flashcards	O
.	O
</s>
<s>
The	O
SuperMemo	B-Application
program	O
stores	O
a	O
database	O
of	O
questions	O
and	O
answers	O
constructed	O
by	O
the	O
user	O
.	O
</s>
<s>
When	O
reviewing	O
information	O
saved	O
in	O
the	O
database	O
,	O
the	O
program	O
uses	O
the	O
SuperMemo	B-Application
algorithm	O
to	O
decide	O
what	O
questions	O
to	O
show	O
the	O
user	O
.	O
</s>
<s>
While	O
the	O
exact	O
algorithm	O
varies	O
with	O
the	O
version	O
of	O
SuperMemo	B-Application
,	O
in	O
general	O
,	O
items	O
that	O
are	O
harder	O
to	O
remember	O
show	O
up	O
more	O
frequently	O
.	O
</s>
<s>
Besides	O
simple	O
text	O
questions	O
and	O
answers	O
,	O
the	O
latest	O
version	O
of	O
SuperMemo	B-Application
supports	O
images	O
,	O
video	O
,	O
and	O
HTML	O
questions	O
and	O
answers	O
.	O
</s>
<s>
Since	O
2002	O
,	O
SuperMemo	B-Application
has	O
had	O
a	O
unique	O
set	O
of	O
features	O
that	O
distinguish	O
it	O
from	O
other	O
spaced	O
repetition	O
programs	O
,	O
called	O
incremental	O
reading	O
(	O
IR	O
or	O
"	O
increading	O
"	O
)	O
.	O
</s>
<s>
The	O
user	O
reads	O
the	O
text	O
inside	O
of	O
SuperMemo	B-Application
,	O
and	O
tools	O
are	O
provided	O
to	O
bookmark	O
one	O
's	O
location	O
in	O
the	O
text	O
and	O
automatically	O
schedule	O
it	O
to	O
be	O
revisited	O
later	O
,	O
extract	O
valuable	O
information	O
,	O
and	O
turn	O
extracts	O
into	O
questions	O
for	O
the	O
user	O
to	O
learn	O
.	O
</s>
<s>
The	O
specific	O
algorithms	O
SuperMemo	B-Application
uses	O
have	O
been	O
published	O
,	O
and	O
re-implemented	O
in	O
other	O
programs	O
.	O
</s>
<s>
Different	O
algorithms	O
have	O
been	O
used	O
;	O
SM	O
–	O
0	O
refers	O
to	O
the	O
original	O
(	O
non-computer-based	O
)	O
algorithm	O
,	O
while	O
SM-2	O
refers	O
to	O
the	O
original	O
computer-based	O
algorithm	O
released	O
in	O
the	O
1987	O
(	O
used	O
in	O
SuperMemo	B-Application
versions	O
1.0	O
through	O
3.0	O
,	O
referred	O
to	O
as	O
SM-2	O
because	O
SuperMemo	B-Application
version	O
2	O
was	O
the	O
most	O
popular	O
of	O
these	O
)	O
.	O
</s>
<s>
Piotr	O
Woźniak	O
,	O
the	O
developer	O
of	O
SuperMemo	B-Application
algorithms	O
,	O
released	O
the	O
description	O
for	O
SM-5	O
in	O
a	O
paper	O
titled	O
Optimization	O
of	O
repetition	O
spacing	O
in	O
the	O
practice	O
of	O
learning	O
.	O
</s>
<s>
In	O
1995	O
,	O
SM-8	O
,	O
which	O
capitalized	O
on	O
data	O
collected	O
by	O
users	O
of	O
SuperMemo	B-Application
6	O
and	O
SuperMemo	B-Application
7	O
and	O
added	O
a	O
number	O
of	O
improvements	O
that	O
strengthened	O
the	O
theoretical	O
validity	O
of	O
the	O
function	O
of	O
optimum	O
intervals	O
and	O
made	O
it	O
possible	O
to	O
accelerate	O
its	O
adaptation	O
,	O
was	O
introduced	O
in	O
SuperMemo	B-Application
8	O
.	O
</s>
<s>
In	O
2002	O
,	O
SM-11	O
,	O
the	O
first	O
SuperMemo	B-Application
algorithm	O
that	O
was	O
resistant	O
to	O
interference	O
from	O
the	O
delay	O
or	O
advancement	O
of	O
repetitions	O
was	O
introduced	O
in	O
SuperMemo	B-Application
11	O
(	O
aka	O
SuperMemo	B-Application
2002	O
)	O
.	O
</s>
<s>
In	O
2011	O
,	O
SM-15	O
,	O
which	O
notably	O
eliminated	O
two	O
weaknesses	O
of	O
SM-11	O
that	O
would	O
show	O
up	O
in	O
heavily	O
overloaded	O
collections	O
with	O
very	O
large	O
item	O
delays	O
,	O
was	O
introduced	O
in	O
Supermemo	B-Application
15	O
.	O
</s>
<s>
In	O
2016	O
,	O
SM-17	O
,	O
the	O
first	O
version	O
of	O
the	O
algorithm	O
to	O
incorporate	O
the	O
two	O
component	O
model	O
of	O
memory	O
,	O
was	O
introduced	O
in	O
SuperMemo	B-Application
17	O
.	O
</s>
<s>
The	O
latest	O
version	O
of	O
the	O
SuperMemo	B-Application
algorithm	O
is	O
SM-18	O
,	O
released	O
in	O
2019	O
.	O
</s>
<s>
The	O
first	O
computer-based	O
SuperMemo	B-Application
algorithm	O
(	O
SM-2	O
)	O
tracks	O
three	O
properties	O
for	O
each	O
card	O
being	O
studied	O
:	O
</s>
<s>
The	O
inter-repetition	O
interval	O
I	O
,	O
which	O
is	O
the	O
length	O
of	O
time	O
(	O
in	O
days	O
)	O
SuperMemo	B-Application
will	O
wait	O
after	O
the	O
previous	O
review	O
before	O
asking	O
the	O
user	O
to	O
review	O
the	O
card	O
again	O
.	O
</s>
<s>
Every	O
time	O
the	O
user	O
starts	O
a	O
review	O
session	O
,	O
SuperMemo	B-Application
provides	O
the	O
user	O
with	O
the	O
cards	O
whose	O
last	O
review	O
occurred	O
at	O
least	O
I	O
days	O
ago	O
.	O
</s>
<s>
After	O
all	O
scheduled	O
reviews	O
are	O
complete	O
,	O
SuperMemo	B-Application
asks	O
the	O
user	O
to	O
re-review	O
any	O
cards	O
they	O
marked	O
with	O
a	O
grade	O
less	O
than	O
4	O
repeatedly	O
until	O
they	O
give	O
a	O
grade	O
≥	O
4	O
.	O
</s>
<s>
Some	O
of	O
the	O
algorithms	O
have	O
been	O
re-implemented	O
in	O
other	O
,	O
often	O
free	B-Application
programs	O
such	O
as	O
Anki	B-Application
,	O
Mnemosyne	B-Language
,	O
and	O
Emacs	B-Operating_System
Org-mode	I-Operating_System
'	O
s	O
Org-drill	O
.	O
</s>
<s>
See	O
full	O
list	B-Application
of	I-Application
flashcard	I-Application
software	I-Application
.	O
</s>
<s>
The	O
SM-2	O
algorithm	O
has	O
proven	O
most	O
popular	O
in	O
other	O
applications	O
,	O
and	O
is	O
used	O
(	O
in	O
modified	O
form	O
)	O
in	O
Anki	B-Application
and	O
Mnemosyne	B-Language
,	O
among	O
others	O
.	O
</s>
