Information Technology Reference
In-Depth Information
4.5.2.8.
Static semantics
The static semantics of the allocation model express the duration of multimodal
presentation
pm
and elementary multimodal presentation
pme
.
It is defined by their time boundaries respectively, via temporal relations
T
and
T
, and a set of properties defined on the syntaxical elements of the model enabling
us to describe the usability properties of the HCI, let us consider the functions
deb
and
end
defined on
PM
as follows:
deb
:
PM → Time ∀pm
i
∈ PMdeb
(
pm
i
) is defined at the beginning of the
pm
i
;
end
:
PM → Time∀pm
i
∈ P Mend
(
pm
i
) is the moment of the end of
pm
i
.
Let
T
be the temporal relation, which associates to each elementary multimodal
presentation associates its start and end moment:
T
:
PM −→ Time× Time
∀pm
i
∈ PM ∃
(
deb
(
pm
i
)
, end
(
pm
i
))
∈ Time× Time
such as:
deb
(
pm
i
)
< end
(
pm
i
) and
T
(
pm
i
)=(
deb
(
pm
i
)
, end
(
pm
i
))
Let us consider the functions
deb
and
end
defined on
PME
as follows:
deb
:
PME → Time ∀pme
i
∈ PME deb
(
pme
i
) is the moment of the
beginning of
pme
i
;
end
:
PME → Time∀pme
i
∈ P ME end
(
pme
i
) is the moment of the end
of
pme
i
.
Let
T
be the temporal relation which associates the moment of the start and end
to each elementary multimodal presentation:
T
:
PME −→ Time× Time
∀pme
i
∈ PME ∃
(
deb
(
pme
i
)
, end
(
pme
i
))
∈ Time× Time
such as
deb
(
pme
i
)
< end
(
pme
i
) and
T
(
pme
i
)=(
deb
(
pme
i
)
, end
(
pme
i
))
There are usability constraints of the interface in output that can be linked to: the
environment (e.g. the noise which detracts from the use of the vocal mode); the system
(the use of a PDA is an argument in favor of graphic modality rather then textual one);
and the user (a hearing impaired user will favor visual mode to auditory mode). In the
aim of describing these constraints we will introduce the following static properties:
- the mode used for the media:
mode
(
med
i
)
∈{visual, auditory, tactile}
.For
example,
mode
(
loud-speaker
)=
vocal
,
mode
(
screen
)=
visual
;
