<s>
In	O
statistics	O
,	O
the	O
Conover	O
squared	B-General_Concept
ranks	I-General_Concept
test	I-General_Concept
is	O
a	O
non-parametric	O
version	O
of	O
the	O
parametric	O
Levene	B-General_Concept
's	I-General_Concept
test	I-General_Concept
for	O
equality	O
of	O
variance	O
.	O
</s>
<s>
Conover	O
's	O
squared	B-General_Concept
ranks	I-General_Concept
test	I-General_Concept
is	O
the	O
only	O
equality	O
of	O
variance	O
test	O
that	O
appears	O
to	O
be	O
non-parametric	O
.	O
</s>
<s>
The	O
squared	B-General_Concept
ranks	I-General_Concept
test	I-General_Concept
is	O
arguably	O
a	O
test	O
of	O
significance	O
of	O
difference	O
of	O
data	O
dispersion	O
not	O
variance	O
per	O
se	O
.	O
</s>
<s>
This	O
becomes	O
important	O
,	O
for	O
example	O
,	O
when	O
the	O
Levene	B-General_Concept
's	I-General_Concept
test	I-General_Concept
fails	O
to	O
satisfy	O
the	O
rather	O
generous	O
conditions	O
for	O
normality	O
associated	O
with	O
that	O
test	O
and	O
is	O
a	O
default	O
alternative	O
under	O
those	O
conditions	O
for	O
certain	O
statistical	O
software	O
programs	O
like	O
the	O
VarianceEquivalenceTest	O
routine	O
in	O
Mathematica	O
.	O
</s>
<s>
In	O
addition	O
to	O
Levene	B-General_Concept
's	I-General_Concept
test	I-General_Concept
,	O
other	O
parametric	O
tests	O
for	O
equality	O
of	O
variance	O
include	O
the	O
Bartlett	O
,	O
Brown-Forsythe	O
,	O
and	O
Fisher	O
Ratio	O
tests	O
.	O
</s>
