<s>
In	O
statistics	O
,	O
the	O
size	O
of	O
a	O
test	O
is	O
the	O
probability	O
of	O
falsely	O
rejecting	O
the	O
null	B-General_Concept
hypothesis	I-General_Concept
.	O
</s>
<s>
For	O
a	O
simple	B-General_Concept
hypothesis	I-General_Concept
,	O
</s>
<s>
In	O
the	O
case	O
of	O
a	O
composite	O
null	B-General_Concept
hypothesis	I-General_Concept
,	O
the	O
size	O
is	O
the	O
supremum	O
over	O
all	O
data	O
generating	O
processes	O
that	O
satisfy	O
the	O
null	B-General_Concept
hypotheses	I-General_Concept
.	O
</s>
<s>
A	O
test	O
is	O
said	O
to	O
have	O
significance	B-General_Concept
level	I-General_Concept
if	O
its	O
size	O
is	O
less	O
than	O
or	O
equal	O
to	O
.	O
</s>
