Information Technology Reference
In-Depth Information
mobile devices increase in data capacity, devices
such as USB sticks and MP3 players are increas-
ingly becoming the vectors for synchronization, so
that perhaps new classes of application and hence
a need for new heuristics will arise in this area.
Much of the early research on mobile platforms
was based around more substantial mobile comput-
ers and (often collaborative) remote applications.
Issues of data synchronization over networks
were crucial and in particular the problems due to
network delays (Davies et al., 1996; Dix, 1995).
This is still a major problem; for example, few
users are aware that SMS is an unreliable mes-
saging medium and can have substantial delays,
especially for international texts. Strangely this
does not seem to be prominent in the current lit-
erature and hence is not reflected in the heuristics.
Perhaps this reflects the belief (as has been the case
for 20 years) that 'soon' everything will be quick
enough, or perhaps simply that empirical work is
usually carried out in areas of high connectivity.
For location-based services, it is important that
users understand the accuracy and other features
of the location estimates. Where information or
other services are based on discretized regions
confusion can arise at boundaries, rather like the
digital radio example. Heuristic 1 applies again
here, making not just location but data about
uncertainty available. However, how this can be
achieved in practice is still a matter for research,
so more detailed general guidelines are not yet
possible.
and comfortable to hold/carry along” and also that
they are “robust to damage” when they inevitably
get banged or dropped. Heuristic 1's focus on
losability/findability reflects the dynamic context
where mobile devices may be put down while
carrying out other tasks.
The social context is also noted in Heuristic
7, “Mobile interaction with the system should be
comfortable and respectful of social conventions”,
and this interacts with the ability to (Heuristic 6)
“dynamically configure the system according to
contextual needs”.
Avoiding embarrassing symphonic ring tones
and similar context-sensitive adaptations has been
the focus of much research and a mobile device
may potentially have access to just the environ-
mental information to make this possible. While
still very much a matter of ongoing research,
this is reflected in several heuristics: (Heuristic
1) “messages regarding … environmental condi-
tions”, (Heuristic 2) “the system should have the
capability to sense its environment”, (Heuristic
3) “user's conceptual model … consistent with
the context”.
Mobile devices are often used in far from
optimal lighting conditions and while moving,
making small fonts hard to read and so further
reducing effective screen size. Both of these
exacerbate the input/output problems of a small
device discussed in the section entitled
The Nature
of Mobile Devices
. In addition, the user is often
performing another task at the same time as us-
ing the mobile device, sometimes related to the
mobile device's function (following a GPS map,
or talking about a task on the phone) and some-
times unrelated (walking round the supermarket
while talking to your mother on your mobile, or
texting under the desk in a lecture). Heuristic 5
particularly picks up on these issues. When do-
ing another task it is essential that the user can
“get the crucial information from the system by
glancing at (
the device
)” and avoid “the need for
the user to use both hands”.
The Context of Mobile Use
Mobile devices are used while walking, (with
care) in vehicles, outside in the rain, on the beach
in the sand; they are often held while trying to do
other things: open doors, carry shopping, pay for
the bus, and in environments with other people.
This rich set of physical and social contexts is
reflected in several of the heuristics.
Heuristic 4 in particular notes the importance
of “Good ergonomics” so that devices are “easy
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