<s>
Theory	O
is	O
becoming	O
an	O
important	O
topic	O
in	O
visualization	B-Application
,	O
expanding	O
from	O
its	O
traditional	O
origins	O
in	O
low-level	O
perception	O
and	O
statistics	O
to	O
an	O
ever-broader	O
array	O
of	O
fields	O
and	O
subfields	O
.	O
</s>
<s>
It	O
includes	O
color	O
theory	O
,	O
visual	O
cognition	O
,	O
visual	O
grammars	O
,	O
interaction	O
theory	O
,	O
visual	B-Application
analytics	I-Application
and	O
information	O
theory	O
.	O
</s>
