Geoscience Reference
In-Depth Information
2.2 Improving Performance: Mobile Usability
As well as straightforward system performance, an additional aspect to be con-
sidered when examining the usability of a 3D City Model on a mobile device is
the usability of the interface to the City Model and the mobile device—how does
the user interact with the device to navigate their way through the model and find
items or areas of interest.
User Interaction with Mobile Devices
(Nielsen and Budiu
2012
) notes that
when designing for mobile, “there's a tension between (a) making content and
navigation salient so that people don't have to work too hard to get there and (b)
designing for a small screen and for slow downloading speeds”. Usability hurdles
include the small screens, difficult input (especially if the user is expected to type
information) and performance issues due to lower bandwidth. (Nielsen and Budiu
2012
) therefore suggests that for small devices, features should be restricted to
those most needed for a mobile use case.
Nielsen and Budiu (
2012
) lists potential interaction with mobile devices as
including:
• Swipe left
• Swipe right
• Tap and hold
• Tap
• Pull down
• Shake
• Pinch
• Pinch vertically
They also note that the most famous generic command for a mobile device with a
touch screen is a pinch-zoom operation (Nielsen and Budiu
2012
).
2.3 Spatial Literacy in 3D Worlds
A third issue related to ensuring that 3D City Models do in fact meet the needs of
end users concerns the issue of spatial literacy within the 3D City Model itself—
which features of a City Model can be used to provide anchor points for naviga-
tion, how does the data within the 3D City Model help the user achieve his/her end
goal? Given the relatively recent emergence of mobile devices with the capability
to visualise 3D datasets in real time, little work has yet been done to understand
how users interact with 3D city models on such devices. A review of work car-
ried out in a 3D context is given by Oulasvirta et al. (
2009
). More recent research
in a mobile 2D map context (Kassi et al.
2013
) shows that the ability of a mobile
device to show the user's current location on a map does assist the cognitive pro-
cess of self-location as it limits the area of the map that the user has to scan to
identify features on the map in relation to features on the ground, highlighting also
