haps cars of the future should be outfitted with joysticks instead of steering wheels! Finally, it might be the
case that the steering task in the game
is not the same as steering a car in the
real world, so that even a fully natural
technique would not necessarily improve performance.
Regardless of the interpretation,
this experiment showed that simply
making interaction techniques more
faithful to the real world does not ensure gains in performance (players,
however, did rate the Wii Wheel as
the most fun technique). In fact, increasing interaction fidelity without
making the technique fully natural
was actually harmful to performance
in this study.
Influence of interaction fidelity in
first-person shooters. Our most recent
studies20 have focused on the combined effects of interaction fidelity
and display fidelity for the “
first-person shooter” (FPS) style of games. We
chose the FPS genre because of its demanding interaction requirements,
variety of user tasks (including travel,
visual search, aiming, and firing), and
relevance to serious gaming applications such as military training.
To achieve the highest-possible
level of display fidelity in these experiments, we used the DiVE systemd at Duke University. The DiVE is
a completely enclosed cube-shaped
3D projection environment that displays high-resolution stereoscopic 3D
graphics on all six sides of the cube
and provides 6-DOF wireless tracking
(see Figure 3). With this system, we
could achieve a very wide range of display and interaction fidelity levels, and
therefore could simulate many different possible gaming setups.
In the first study, we wanted to explore the general effects of interaction fidelity and display fidelity, and
find out whether one influenced the
other. Thus, we designed two levels of
each variable, representing “low” and
The low interaction fidelity condition used a typical mouse and keyboard interface for FPS games, with
the mouse being used to turn, aim,
and fire, and the keyboard to travel
through the virtual world. The high
We found the
use of head
errors for the
judgment task, and
that head tracking
in combination with
interaction fidelity condition used a
tracked handheld controller for direct
aiming and firing, and a technique
called the “human joystick” for travel.
In the human joystick technique, the
user would physically step in the desired travel direction, with movement
starting once the user stepped outside
a small circular area, and the speed
of movement proportional to the distance from the center. Although this
technique is not highly natural, it has
higher interaction fidelity than the
keyboard technique due to its use of
physical leg movements with direction mapped directly to the environment. A more natural technique such
as redirected walking was not practical in the DiVE.
The low display fidelity condition
used a single screen of the DiVE without stereoscopic graphics. It therefore
also required a method for rotating
the view, so we provided a technique
that turned the viewpoint when the
cursor was near the edge of the screen.
The high display fidelity condition
used all six screens of the DiVE with
stereoscopic graphics enabled, so users could turn physically to view the
environment in different directions.
This meant that for the mouse and keyboard conditions, users had to be able
to turn the mouse and keyboard with
them; we placed the devices on a turntable for this purpose.
Participants were placed in an FPS
game that required them to navigate
several rooms with varying shapes,
sizes, and obstacles, destroying “bots”
(enemies) along the way. We measured performance metrics such as
completion time, shooting accuracy,
and damage taken. We also used questionnaires to ask participants about
their sense of presence, 30 engagement
with the game, 6 and opinions of interface usability.
Performance results were strongly
in favor of two conditions: the condition with low display fidelity and low
interaction fidelity, and the condition
with high display fidelity and high interaction fidelity. These conditions are
similar to traditional gaming setups
and high-end VR setups that simulate
the real world as closely as possible.
The other two combinations were unfamiliar to users (despite the fact that
they were trained on each combina-