<s>
The	O
probability	B-Application
plot	I-Application
correlation	I-Application
coefficient	I-Application
(	O
PPCC	O
)	O
plot	O
is	O
a	O
graphical	B-Application
technique	I-Application
for	O
identifying	O
the	O
shape	O
parameter	O
for	O
a	O
distributional	O
family	O
that	O
best	O
describes	O
the	O
data	O
set	O
.	O
</s>
<s>
The	O
technique	O
is	O
simply	O
"	O
plot	O
the	O
probability	B-Application
plot	I-Application
correlation	I-Application
coefficients	I-Application
for	O
different	O
values	O
of	O
the	O
shape	O
parameter	O
,	O
and	O
choose	O
whichever	O
value	O
yields	O
the	O
best	O
fit	O
"	O
.	O
</s>
<s>
The	O
PPCC	B-Application
plot	I-Application
is	O
formed	O
by	O
:	O
</s>
<s>
Vertical	O
axis	O
:	O
Probability	B-Application
plot	I-Application
correlation	I-Application
coefficient	I-Application
;	O
</s>
<s>
For	O
better	O
precision	O
,	O
two	O
iterations	O
of	O
the	O
PPCC	B-Application
plot	I-Application
can	O
be	O
generated	O
;	O
the	O
first	O
is	O
for	O
finding	O
the	O
right	O
neighborhood	O
and	O
the	O
second	O
is	O
for	O
fine	O
tuning	O
the	O
estimate	O
.	O
</s>
<s>
The	O
PPCC	B-Application
plot	I-Application
is	O
used	O
first	O
to	O
find	O
a	O
good	O
value	O
of	O
the	O
shape	O
parameter	O
.	O
</s>
<s>
The	O
PPCC	B-Application
plot	I-Application
answers	O
the	O
following	O
questions	O
:	O
</s>
<s>
In	O
addition	O
to	O
finding	O
a	O
good	O
choice	O
for	O
estimating	O
the	O
shape	O
parameter	O
of	O
a	O
given	O
distribution	O
,	O
the	O
PPCC	B-Application
plot	I-Application
can	O
be	O
useful	O
in	O
deciding	O
which	O
distributional	O
family	O
is	O
most	O
appropriate	O
.	O
</s>
<s>
For	O
example	O
,	O
given	O
a	O
set	O
of	O
reliability	O
data	O
,	O
one	O
might	O
generate	O
PPCC	B-Application
plots	I-Application
for	O
a	O
Weibull	O
,	O
lognormal	O
,	O
gamma	O
,	O
and	O
inverse	O
Gaussian	O
distributions	O
,	O
and	O
possibly	O
others	O
,	O
on	O
a	O
single	O
page	O
.	O
</s>
<s>
This	O
one	O
page	O
would	O
show	O
the	O
best	O
value	O
for	O
the	O
shape	O
parameter	O
for	O
several	O
distributions	O
and	O
would	O
additionally	O
indicate	O
which	O
of	O
these	O
distributional	O
families	O
provides	O
the	O
best	O
fit	O
(	O
as	O
measured	O
by	O
the	O
maximum	O
probability	B-Application
plot	I-Application
correlation	I-Application
coefficient	I-Application
)	O
.	O
</s>
<s>
The	O
Tukey	O
lambda	O
PPCC	B-Application
plot	I-Application
,	O
with	O
shape	O
parameter	O
λ	O
,	O
is	O
particularly	O
useful	O
for	O
symmetric	O
distributions	O
.	O
</s>
<s>
If	O
the	O
Tukey	O
lambda	O
PPCC	B-Application
plot	I-Application
gives	O
a	O
maximum	O
value	O
near	O
0.14	O
,	O
one	O
can	O
reasonably	O
conclude	O
that	O
the	O
normal	O
distribution	O
is	O
a	O
good	O
model	O
for	O
the	O
data	O
.	O
</s>
<s>
If	O
the	O
maximum	O
value	O
is	O
greater	O
than	O
0.14	O
,	O
this	O
implies	O
a	O
short-tailed	B-Error_Name
distribution	I-Error_Name
such	O
as	O
the	O
Beta	O
or	O
uniform	O
.	O
</s>
<s>
The	O
Tukey-lambda	O
PPCC	B-Application
plot	I-Application
is	O
used	O
to	O
suggest	O
an	O
appropriate	O
distribution	O
.	O
</s>
