Biomedical Engineering Reference
In-Depth Information
interacting on foot is that, implicitly, both feet are involved in touching the interface,
due to requirements of movement and of maintaining balance. In everyday actions,
like striking a soccer ball, weight is often shifted onto one foot, which specifies
an anchored location, while the opposite is used to perform an action within the
reachable area. Thus, floor interfaces that involve movement may share similarities
to bimanual interaction in HCI, a connection that provides another potential avenue
of future investigation.
17.4.5 Application: Geospatial Data Navigation
The ubiquity of multi-touch mobile devices and computers has popularized the use
of two-finger gestures to navigate and control zoom level in the display of data via
a touch screen. Such an approach focuses on the fingers as a means of providing
input and may not be appropriate for settings in which the display surface is not
amenable to finger-based interaction, when the hands are occupied, or when the data
visualization application occupies a larger volume of space. We argue that this focus
has limited the possibilities for carrying out complex exploration tasks in ways that
leverage the capabilities we exploit naturally in the physical world.
For target acquisition tasks, e.g., menu and object selection, the accuracy and
speed of the input primitives are important. In contrast, for spatial navigation tasks,
e.g., panning and zooming, using dragging, resizing, and scrolling operations, less
accuracy is often acceptable. Consequently, spatial navigation is likely an appropriate
candidate for foot-based input, leaving the hands free, in parallel, to specialize on
the more time- and accuracy-critical operations [
23
]. For instance, in the context of
collaborative design or decision making, e.g., urban and architectural planning, or
emergency and crisis management [
2
,
20
,
29
], different roles are appropriate for foot
input and hand input. Specifically, the feet might be better suited to controlling the
location or region of interest, while the hands are used to perform other more critical
or complex input tasks such as target selection, annotation, or drawing in the virtual
design space, or dispatching tasks in emergency situations. Moreover, this represents
a compelling alternative for scenarios where use of the hands is inconvenient. For
example, in the context of airport information kiosks, where users might be carrying
luggage, it may be desirable and appropriate to obtain directions to ones gate through
a foot-based interface.
17.4.6 Foot-Based Gestures for Geospatial Navigation
The authors of this chapter implemented an application and several foot-based
interaction methods for navigating geospatial data sets presented through the
multitouch-sensitive floor surface described in the foregoing. In contrast to prior
work, which has focused on foot-based interaction at a fixed location, we investigated
