<s>
Multimodal	B-Application
interaction	I-Application
provides	O
the	O
user	O
with	O
multiple	O
modes	B-General_Concept
of	I-General_Concept
interacting	I-General_Concept
with	O
a	O
system	O
.	O
</s>
<s>
A	O
multimodal	B-Application
interface	I-Application
provides	O
several	O
distinct	O
tools	O
for	O
input	B-General_Concept
and	I-General_Concept
output	I-General_Concept
of	O
data	O
.	O
</s>
<s>
Multimodal	O
human-computer	O
interaction	O
refers	O
to	O
the	O
"	O
interaction	O
with	O
the	O
virtual	O
and	O
physical	O
environment	O
through	O
natural	O
modes	O
of	O
communication	O
"	O
,	O
This	O
implies	O
that	O
multimodal	B-Application
interaction	I-Application
enables	O
a	O
more	O
free	O
and	O
natural	O
communication	O
,	O
interfacing	O
users	O
with	O
automated	O
systems	O
in	O
both	O
input	B-General_Concept
and	I-General_Concept
output	I-General_Concept
.	O
</s>
<s>
Specifically	O
,	O
multimodal	O
systems	O
can	O
offer	O
a	O
flexible	O
,	O
efficient	O
and	O
usable	B-General_Concept
environment	O
allowing	O
users	O
to	O
interact	O
through	O
input	O
modalities	B-General_Concept
,	O
such	O
as	O
speech	B-Application
,	O
handwriting	B-Application
,	O
hand	B-General_Concept
gesture	I-General_Concept
and	O
gaze	B-General_Concept
,	O
and	O
to	O
receive	O
information	O
by	O
the	O
system	O
through	O
output	O
modalities	B-General_Concept
,	O
such	O
as	O
speech	B-Application
synthesis	I-Application
,	O
smart	O
graphics	O
and	O
other	O
modalities	B-General_Concept
,	O
opportunely	O
combined	O
.	O
</s>
<s>
Then	O
a	O
multimodal	O
system	O
has	O
to	O
recognize	O
the	O
inputs	O
from	O
the	O
different	O
modalities	B-General_Concept
combining	O
them	O
according	O
to	O
temporal	O
and	O
contextual	O
constraints	O
in	O
order	O
to	O
allow	O
their	O
interpretation	O
.	O
</s>
<s>
Naturalness	O
and	O
flexibility	O
can	O
produce	O
more	O
than	O
one	O
interpretation	O
for	O
each	O
different	O
modality	B-General_Concept
(	O
channel	O
)	O
and	O
for	O
their	O
simultaneous	O
use	O
,	O
and	O
they	O
consequently	O
can	O
produce	O
multimodal	O
ambiguity	O
generally	O
due	O
to	O
imprecision	O
,	O
noises	O
or	O
other	O
similar	O
factors	O
.	O
</s>
<s>
The	O
pervasive	O
use	O
of	O
mobile	O
devices	O
,	O
sensors	O
and	O
web	O
technologies	O
can	O
offer	O
adequate	O
computational	O
resources	O
to	O
manage	O
the	O
complexity	O
implied	O
by	O
the	O
multimodal	B-Application
interaction	I-Application
.	O
</s>
<s>
"	O
Using	O
cloud	O
for	O
involving	O
shared	O
computational	O
resources	O
in	O
managing	O
the	O
complexity	O
of	O
multimodal	B-Application
interaction	I-Application
represents	O
an	O
opportunity	O
.	O
</s>
<s>
Two	O
major	O
groups	O
of	O
multimodal	B-Application
interfaces	I-Application
have	O
merged	O
,	O
one	O
concerned	O
in	O
alternate	O
input	O
methods	O
and	O
the	O
other	O
in	O
combined	O
input/output	B-General_Concept
.	O
</s>
<s>
The	O
first	O
group	O
of	O
interfaces	O
combined	O
various	O
user	B-General_Concept
input	I-General_Concept
modes	O
beyond	O
the	O
traditional	O
keyboard	B-Device
and	O
mouse	O
input/output	O
,	O
such	O
as	O
speech	B-Application
,	O
pen	O
,	O
touch	O
,	O
manual	O
gestures	O
,	O
gaze	B-General_Concept
and	O
head	O
and	O
body	O
movements	O
.	O
</s>
<s>
The	O
most	O
common	O
such	O
interface	O
combines	O
a	O
visual	O
modality	B-General_Concept
(	O
e.g.	O
</s>
<s>
a	O
display	O
,	O
keyboard	B-Device
,	O
and	O
mouse	B-Device
)	O
with	O
a	O
voice	O
modality	B-General_Concept
(	O
speech	B-Application
recognition	I-Application
for	O
input	O
,	O
speech	B-Application
synthesis	I-Application
and	O
recorded	O
audio	O
for	O
output	O
)	O
.	O
</s>
<s>
However	O
other	O
modalities	B-General_Concept
,	O
such	O
as	O
pen-based	O
input	O
or	O
haptic	B-Device
input/output	B-General_Concept
may	O
be	O
used	O
.	O
</s>
<s>
Multimodal	B-Application
user	I-Application
interfaces	I-Application
are	O
a	O
research	O
area	O
in	O
human-computer	O
interaction	O
(	O
HCI	O
)	O
.	O
</s>
<s>
The	O
advantage	O
of	O
multiple	O
input	O
modalities	B-General_Concept
is	O
increased	O
usability	B-General_Concept
:	O
the	O
weaknesses	O
of	O
one	O
modality	B-General_Concept
are	O
offset	O
by	O
the	O
strengths	O
of	O
another	O
.	O
</s>
<s>
Visually	O
impaired	O
users	O
rely	O
on	O
the	O
voice	O
modality	B-General_Concept
with	O
some	O
keypad	O
input	O
.	O
</s>
<s>
Hearing-impaired	O
users	O
rely	O
on	O
the	O
visual	O
modality	B-General_Concept
with	O
some	O
speech	B-Application
input	O
.	O
</s>
<s>
wearing	O
gloves	O
in	O
a	O
very	O
noisy	O
environment	O
,	O
driving	O
,	O
or	O
needing	O
to	O
enter	O
a	O
credit	O
card	O
number	O
in	O
a	O
public	O
place	O
)	O
and	O
will	O
simply	O
use	O
the	O
appropriate	O
modalities	B-General_Concept
as	O
desired	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
a	O
multimodal	O
application	O
that	O
requires	O
users	O
to	O
be	O
able	O
to	O
operate	O
all	O
modalities	B-General_Concept
is	O
very	O
poorly	O
designed	O
.	O
</s>
<s>
The	O
most	O
common	O
form	O
of	O
input	O
multimodality	O
in	O
the	O
market	O
makes	O
use	O
of	O
the	O
XHTML+Voice	O
(	O
aka	O
X+V	O
)	O
Web	O
markup	O
language	O
,	O
an	O
open	O
specification	B-Application
developed	O
by	O
IBM	O
,	O
Motorola	O
,	O
and	O
Opera	B-Application
Software	O
.	O
</s>
<s>
X+V	O
is	O
currently	O
under	O
consideration	O
by	O
the	O
W3C	O
and	O
combines	O
several	O
W3C	O
Recommendations	O
including	O
XHTML	B-Language
for	O
visual	O
markup	O
,	O
VoiceXML	B-Application
for	O
voice	O
markup	O
,	O
and	O
XML	B-Language
Events	I-Language
,	O
a	O
standard	O
for	O
integrating	O
XML	B-Protocol
languages	O
.	O
</s>
<s>
Multimodal	B-Protocol
browsers	I-Protocol
supporting	O
X+V	O
include	O
IBM	O
WebSphere	O
Everyplace	O
Multimodal	O
Environment	O
,	O
Opera	B-Application
for	O
Embedded	B-Architecture
Linux	B-Application
and	O
Windows	B-Application
,	O
and	O
ACCESS	O
Systems	O
NetFront	B-Operating_System
for	O
Windows	B-Operating_System
Mobile	I-Operating_System
.	O
</s>
<s>
To	O
develop	O
multimodal	O
applications	O
,	O
software	B-Application
developers	I-Application
may	O
use	O
a	O
software	B-Application
development	I-Application
kit	I-Application
,	O
such	O
as	O
IBM	O
WebSphere	O
Multimodal	O
Toolkit	O
,	O
based	O
on	O
the	O
open	B-License
source	I-License
Eclipse	B-Application
framework	B-Architecture
,	O
which	O
includes	O
an	O
X+V	O
debugger	B-Application
,	O
editor	B-Application
,	O
and	O
simulator	O
.	O
</s>
<s>
Interface	O
designers	O
have	O
also	O
started	O
to	O
make	O
use	O
of	O
other	O
modalities	B-General_Concept
,	O
such	O
as	O
touch	O
and	O
olfaction	O
.	O
</s>
<s>
The	O
information	O
that	O
is	O
presented	O
via	O
several	O
modalities	B-General_Concept
is	O
merged	O
and	O
refers	O
to	O
various	O
aspects	O
of	O
the	O
same	O
process	O
.	O
</s>
<s>
An	O
important	O
step	O
in	O
multimodal	B-Application
interface	I-Application
design	O
is	O
the	O
creation	O
of	O
natural	O
mappings	O
between	O
modalities	B-General_Concept
and	O
the	O
information	O
and	O
tasks	O
.	O
</s>
<s>
Speech	B-Application
output	O
,	O
one	O
form	O
of	O
auditory	O
information	O
,	O
received	O
considerable	O
attention	O
.	O
</s>
<s>
Several	O
guidelines	O
have	O
been	O
developed	O
for	O
the	O
use	O
of	O
speech	B-Application
.	O
</s>
<s>
Michaelis	O
and	O
Wiggins	O
(	O
1982	O
)	O
suggested	O
that	O
speech	B-Application
output	O
should	O
be	O
used	O
for	O
simple	O
short	O
messages	O
that	O
will	O
not	O
be	O
referred	O
to	O
later	O
.	O
</s>
<s>
It	O
was	O
also	O
recommended	O
that	O
speech	B-Application
should	O
be	O
generated	O
in	O
time	O
and	O
require	O
an	O
immediate	O
response	O
.	O
</s>
<s>
deleting	O
a	O
file	O
,	O
open	O
a	O
folder	O
,	O
error	O
)	O
,	O
speech	B-Application
output	O
for	O
presenting	O
navigational	O
guidance	O
in	O
vehicles	O
,	O
and	O
speech	B-Application
output	O
for	O
warning	O
pilots	O
on	O
modern	O
airplane	O
cockpits	O
.	O
</s>
<s>
The	O
process	O
of	O
integrating	O
information	O
from	O
various	O
input	O
modalities	B-General_Concept
and	O
combining	O
them	O
into	O
a	O
complete	O
command	O
is	O
referred	O
as	O
multimodal	O
fusion	O
.	O
</s>
<s>
In	O
the	O
hybrid	O
multi-level	O
fusion	O
,	O
the	O
integration	O
of	O
input	O
modalities	B-General_Concept
is	O
distributed	O
among	O
the	O
recognition	O
and	O
decision	O
levels	O
.	O
</s>
<s>
It	O
is	O
obtained	O
by	O
merging	O
information	O
that	O
are	O
conveyed	O
via	O
several	O
modalities	B-General_Concept
by	O
considering	O
the	O
different	O
types	O
of	O
cooperation	O
between	O
several	O
modalities	B-General_Concept
,	O
the	O
time	O
relationships	O
among	O
the	O
involved	O
modalities	B-General_Concept
and	O
the	O
relationships	O
between	O
chunks	O
of	O
information	O
connected	O
with	O
these	O
modalities	B-General_Concept
.	O
</s>
<s>
The	O
natural	O
mapping	O
between	O
the	O
multimodal	O
input	O
,	O
which	O
is	O
provided	O
by	O
several	O
interaction	O
modalities	B-General_Concept
(	O
visual	O
and	O
auditory	O
channel	O
and	O
sense	O
of	O
touch	O
)	O
,	O
and	O
information	O
and	O
tasks	O
imply	O
to	O
manage	O
the	O
typical	O
problems	O
of	O
human-human	O
communication	O
,	O
such	O
as	O
ambiguity	O
.	O
</s>
<s>
A	O
multimodal	O
ambiguity	O
arises	O
both	O
,	O
if	O
an	O
element	O
,	O
which	O
is	O
provided	O
by	O
one	O
modality	B-General_Concept
,	O
has	O
more	O
than	O
one	O
interpretation	O
(	O
i.e.	O
</s>
<s>
ambiguities	O
are	O
propagated	O
at	O
the	O
multimodal	O
level	O
)	O
,	O
and/or	O
if	O
elements	O
,	O
connected	O
with	O
each	O
modality	B-General_Concept
,	O
are	O
univocally	O
interpreted	O
,	O
but	O
information	O
referred	O
to	O
different	O
modalities	B-General_Concept
are	O
incoherent	O
at	O
the	O
syntactic	O
or	O
the	O
semantic	O
level	O
(	O
i.e.	O
</s>
<s>
repetition	O
by	O
modality	B-General_Concept
,	O
granularity	O
of	O
repair	O
and	O
undo	O
,	O
and	O
choice	O
.	O
</s>
