<s>
In	O
statistics	O
,	O
Bartlett	B-General_Concept
's	I-General_Concept
test	I-General_Concept
,	O
named	O
after	O
Maurice	O
Stevenson	O
Bartlett	O
,	O
is	O
used	O
to	O
test	O
homoscedasticity	B-General_Concept
,	O
that	O
is	O
,	O
if	O
multiple	O
samples	O
are	O
from	O
populations	O
with	O
equal	O
variances	O
.	O
</s>
<s>
Some	O
statistical	O
tests	O
,	O
such	O
as	O
the	O
analysis	B-General_Concept
of	I-General_Concept
variance	I-General_Concept
,	O
assume	O
that	O
variances	O
are	O
equal	O
across	O
groups	O
or	O
samples	O
,	O
which	O
can	O
be	O
verified	O
with	O
Bartlett	B-General_Concept
's	I-General_Concept
test	I-General_Concept
.	O
</s>
<s>
In	O
a	O
Bartlett	B-General_Concept
test	I-General_Concept
,	O
we	O
construct	O
the	O
null	O
and	O
alternative	O
hypothesis	O
.	O
</s>
<s>
The	O
test	O
procedure	O
due	O
to	O
M.S.E	O
(	O
Mean	O
Square	O
Error/Estimator	O
)	O
Bartlett	B-General_Concept
test	I-General_Concept
is	O
represented	O
here	O
.	O
</s>
<s>
Bartlett	B-General_Concept
's	I-General_Concept
test	I-General_Concept
is	O
sensitive	O
to	O
departures	O
from	O
normality	O
.	O
</s>
<s>
That	O
is	O
,	O
if	O
the	O
samples	O
come	O
from	O
non-normal	O
distributions	O
,	O
then	O
Bartlett	B-General_Concept
's	I-General_Concept
test	I-General_Concept
may	O
simply	O
be	O
testing	O
for	O
non-normality	O
.	O
</s>
<s>
Levene	B-General_Concept
's	I-General_Concept
test	I-General_Concept
and	O
the	O
Brown	B-General_Concept
–	I-General_Concept
Forsythe	I-General_Concept
test	I-General_Concept
are	O
alternatives	O
to	O
the	O
Bartlett	B-General_Concept
test	I-General_Concept
that	O
are	O
less	O
sensitive	O
to	O
departures	O
from	O
normality	O
.	O
</s>
<s>
Bartlett	B-General_Concept
's	I-General_Concept
test	I-General_Concept
is	O
used	O
to	O
test	O
the	O
null	O
hypothesis	O
,	O
H0	O
that	O
all	O
k	O
population	O
variances	O
are	O
equal	O
against	O
the	O
alternative	O
that	O
at	O
least	O
two	O
are	O
different	O
.	O
</s>
<s>
Bartlett	B-General_Concept
's	I-General_Concept
test	I-General_Concept
is	O
a	O
modification	O
of	O
the	O
corresponding	O
likelihood	B-General_Concept
ratio	I-General_Concept
test	I-General_Concept
designed	O
to	O
make	O
the	O
approximation	O
to	O
the	O
distribution	O
better	O
(	O
Bartlett	O
,	O
1937	O
)	O
.	O
</s>
