<s>
In	O
statistics	O
,	O
a	O
P	B-Application
–	I-Application
P	I-Application
plot	I-Application
(	O
probability	O
–	O
probability	O
plot	O
or	O
percent	O
–	O
percent	O
plot	O
or	O
P	O
value	O
plot	O
)	O
is	O
a	O
probability	O
plot	O
for	O
assessing	O
how	O
closely	O
two	O
data	B-General_Concept
sets	I-General_Concept
agree	O
,	O
or	O
for	O
assessing	O
how	O
closely	O
a	O
dataset	B-General_Concept
fits	O
a	O
particular	O
model	O
.	O
</s>
<s>
This	O
behavior	O
is	O
similar	O
to	O
that	O
of	O
the	O
more	O
widely	O
used	O
Q	B-Application
–	I-Application
Q	I-Application
plot	I-Application
,	O
with	O
which	O
it	O
is	O
often	O
confused	O
.	O
</s>
<s>
A	O
P	B-Application
–	I-Application
P	I-Application
plot	I-Application
plots	O
two	O
cumulative	O
distribution	O
functions	O
(	O
cdfs	O
)	O
against	O
each	O
other	O
:	O
</s>
<s>
As	O
the	O
above	O
example	O
illustrates	O
,	O
if	O
two	O
distributions	O
are	O
separated	O
in	O
space	O
,	O
the	O
P	B-Application
–	I-Application
P	I-Application
plot	I-Application
will	O
give	O
very	O
little	O
data	O
–	O
it	O
is	O
only	O
useful	O
for	O
comparing	O
probability	O
distributions	O
that	O
have	O
nearby	O
or	O
equal	O
location	O
.	O
</s>
<s>
P	B-Application
–	I-Application
P	I-Application
plots	I-Application
are	O
sometimes	O
limited	O
to	O
comparisons	O
between	O
two	O
samples	O
,	O
rather	O
than	O
comparison	O
of	O
a	O
sample	O
to	O
a	O
theoretical	O
model	O
distribution	O
.	O
</s>
<s>
This	O
choice	O
of	O
"	O
plotting	O
position	O
"	O
(	O
choice	O
of	O
quantile	O
of	O
the	O
theoretical	O
distribution	O
)	O
has	O
occasioned	O
less	O
controversy	O
than	O
the	O
choice	O
for	O
Q	B-Application
–	I-Application
Q	I-Application
plots	I-Application
.	O
</s>
<s>
A	O
P	B-Application
–	I-Application
P	I-Application
plot	I-Application
can	O
be	O
used	O
as	O
a	O
graphical	O
adjunct	O
to	O
a	O
tests	O
of	O
the	O
fit	O
of	O
probability	O
distributions	O
,	O
with	O
additional	O
lines	O
being	O
included	O
on	O
the	O
plot	O
to	O
indicate	O
either	O
specific	O
acceptance	O
regions	O
or	O
the	O
range	O
of	O
expected	O
departure	O
from	O
the	O
1:1	O
line	O
.	O
</s>
<s>
An	O
improved	O
version	O
of	O
the	O
P	B-Application
–	I-Application
P	I-Application
plot	I-Application
,	O
called	O
the	O
SP	O
or	O
S	O
–	O
P	O
plot	O
,	O
is	O
available	O
,	O
which	O
makes	O
use	O
of	O
a	O
variance-stabilizing	B-General_Concept
transformation	I-General_Concept
to	O
create	O
a	O
plot	O
on	O
which	O
the	O
variations	O
about	O
the	O
1:1	O
line	O
should	O
be	O
the	O
same	O
at	O
all	O
locations	O
.	O
</s>
