<s>
Generalized	B-Algorithm
Procrustes	I-Algorithm
analysis	I-Algorithm
(	O
GPA	O
)	O
is	O
a	O
method	O
of	O
statistical	O
analysis	O
that	O
can	O
be	O
used	O
to	O
compare	O
the	O
shapes	O
of	O
objects	O
,	O
or	O
the	O
results	O
of	O
surveys	O
,	O
interviews	O
,	O
or	O
panels	O
.	O
</s>
<s>
GPA	O
is	O
one	O
way	O
to	O
make	O
sense	O
of	O
free-choice	O
profiling	O
data	O
;	O
other	O
ways	O
can	O
be	O
multiple	B-Algorithm
factor	I-Algorithm
analysis	I-Algorithm
(	O
MFA	O
)	O
,	O
or	O
the	O
STATIS	O
method	O
.	O
</s>
<s>
Generalized	B-Algorithm
Procrustes	I-Algorithm
analysis	I-Algorithm
estimates	O
the	O
scaling	O
factor	O
applied	O
to	O
respondent	O
scale	O
usage	O
,	O
generating	O
a	O
weighting	O
factor	O
that	O
is	O
used	O
to	O
compensate	O
for	O
individual	O
scale	O
usage	O
differences	O
.	O
</s>
<s>
Unlike	O
measures	O
such	O
as	O
a	O
principal	B-Application
component	I-Application
analysis	I-Application
,	O
GPA	O
uses	O
individual	O
level	O
data	O
and	O
a	O
measure	O
of	O
variance	O
is	O
utilized	O
in	O
the	O
analysis	O
.	O
</s>
<s>
The	O
Procrustes	B-Algorithm
distance	I-Algorithm
provides	O
a	O
metric	O
to	O
minimize	O
in	O
order	O
to	O
superimpose	B-Algorithm
a	O
pair	O
of	O
shape	O
instances	O
annotated	O
by	O
landmark	B-General_Concept
points	I-General_Concept
.	O
</s>
<s>
GPA	O
applies	O
the	O
Procrustes	B-Algorithm
analysis	I-Algorithm
method	O
to	O
superimpose	B-Algorithm
a	O
population	O
of	O
shapes	O
instead	O
of	O
only	O
two	O
shape	O
instances	O
.	O
</s>
<s>
if	O
the	O
Procrustes	B-Algorithm
distance	I-Algorithm
between	O
the	O
mean	O
shape	O
and	O
the	O
reference	O
is	O
above	O
a	O
certain	O
threshold	O
,	O
set	O
the	O
reference	O
to	O
mean	O
shape	O
and	O
continue	O
to	O
step	O
2	O
.	O
</s>
