<s>
SUDAAN	B-Application
is	O
a	O
proprietary	B-Application
statistical	O
software	O
package	O
for	O
the	O
analysis	O
of	O
correlated	O
data	O
,	O
including	O
correlated	O
data	O
encountered	O
in	O
complex	O
sample	O
surveys	O
.	O
</s>
<s>
SUDAAN	B-Application
originated	O
in	O
1972	O
at	O
RTI	O
International	O
(	O
the	O
trade	O
name	O
of	O
Research	O
Triangle	O
Institute	O
)	O
.	O
</s>
<s>
,	O
released	O
in	O
May	O
2018	O
,	O
is	O
a	O
single	O
program	O
consisting	O
of	O
a	O
family	O
of	O
thirteen	O
analytic	O
procedures	O
used	O
to	O
analyze	O
data	O
from	O
complex	O
sample	O
surveys	O
and	O
other	O
observational	O
and	O
experimental	O
studies	O
involving	O
repeated	O
measures	O
and	O
cluster-correlated	B-Algorithm
data	I-Algorithm
.	O
</s>
<s>
SUDAAN	B-Application
enables	O
the	O
analysis	O
of	O
correlated	O
data	O
encountered	O
in	O
various	O
fields	O
of	O
statistical	O
research	O
,	O
including	O
:	O
</s>
<s>
SUDAAN	B-Application
's	O
strength	O
lies	O
in	O
its	O
ability	O
to	O
compute	O
standard	B-General_Concept
errors	I-General_Concept
of	O
ratio	O
estimates	O
,	O
means	O
,	O
totals	O
,	O
regression	O
coefficients	O
,	O
and	O
other	O
statistics	O
in	O
accordance	O
with	O
the	O
sample	O
design	O
,	O
greatly	O
increasing	O
the	O
accuracy	O
and	O
validity	O
of	O
results	O
.	O
</s>
<s>
Many	O
,	O
if	O
not	O
most	O
,	O
data	B-General_Concept
sets	I-General_Concept
require	O
attention	O
to	O
correlation	O
and	O
weighting	B-General_Concept
,	O
but	O
few	O
statistical	O
software	O
packages	O
offer	O
the	O
user	O
the	O
opportunity	O
to	O
specify	O
how	O
data	O
are	O
correlated	O
and	O
weighted	B-Algorithm
.	O
</s>
<s>
For	O
many	O
years	O
,	O
SUDAAN	B-Application
remained	O
the	O
only	O
broadly	O
applicable	O
software	O
for	O
analysis	O
of	O
correlated	O
and	O
weighted	B-Algorithm
data	O
.	O
</s>
<s>
Currently	O
,	O
all	O
nine	O
of	O
SUDAAN	B-Application
's	O
analytic	O
procedures	O
offer	O
three	O
popular	O
robust	O
variance	O
estimation	O
methods	O
:	O
</s>
<s>
SUDAAN	B-Application
functions	O
on	O
many	O
computing	O
platforms	O
—	O
including	O
Windows	O
7/10	O
,	O
DOS	O
,	O
and	O
LINUX	O
—	O
either	O
as	O
a	O
stand-alone	O
statistical	O
software	O
tool	O
,	O
or	O
in	O
SAS-callable	O
format	O
(	O
SAS	O
Version	O
9	O
)	O
.	O
</s>
