Instrumented Usability Analysis for Mobile Devices - Human-Computer Interaction and Innovation in Handheld, Mobile and Wearable Technologies - page 5

Figure 2. Text entry while seated in a car. The number of characters entered per second is plotted to the
right of the acceleration time series (the vertical lines in the left plot are individual key-press events).

understand how users interact with the devices,
and so further improve the designs.

allows us to gain a greater insight into the users
actions and disturbances during the study. Al-
though this example specifically examines users
walking patterns sensed through an accelerometer,
the techniques discussed can be applied to a wide
range of contexts.
Given the importance of devices being used
while the user is walking, and the difficulty re-
searchers have had about getting detailed insight
into user behaviour, down to the level of each
step taken, we now concentrate on the example

DETAILED CASE STUDY OF
WALKING AND TAPPING

Here, we present a detailed example of an instru-
mented usability study to demonstrate the benefits
of this approach. Standard usability time and error
metrics are gathered, while the instrumentation

Figure 3. Text entry in a range of conditions. The number of characters entered per second is plotted to
the right of the acceleration time series (the purple vertical lines in the left plot are individual key-press
events, and the black ones delineate the different walking conditions).