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7.3. Experimental Protocol
Figure 7.2: Phasespace impulse glove.
7.3 Experimental Protocol
We started off the experiment by telling the participants that they would be set in a city scene
filled with characters walking up and down the street. We told them that they would have
to evaluate various modes of this same scene in a CAVE environment by answering a set of
questions. Each participant was asked to test the system individually (without any of other
participants around) in order to keep them naive towards our expectations. Before starting
the experiment, the participants were asked to go through various calibration steps. The
first consisted in calibrating the eye-tracker for those who used the combined system. The
calibration procedure in this case was the same as discussed in the previous experiments.
The second calibration procedure consisted in recording a reference waving gesture in order
to be used for the gesture recognition. We then asked them to enter the CAVE environment
in which we projected the scene. This scene depicted a city street in which a crowd of
characters was walking around, as depicted in Figure 5.4.
With this experiment, we first wanted to make sure that the participants could understand
the difference between the various modes. More importantly, we wanted to verify whether
there would be the same bias towards always attentive characters as in the previous experiment
or not. Finally, we wanted to verify whether immersion and anxiety increased with
gaze. In the case of anxiety, however, we did not expect to obtain clear results since we did
not test the application on a phobic population but on a healthy one.
We determined each participant’s region of interest throughout the experiment by analyzing
their POR determined by the coupled eye- and head-tracking, or by simply using head
orientation, depending on the setup. Each participant was then presented the four different
modes as described in Chapter 5 in pseudo-random order. This was done to remove the order
variable. We then asked them to move around in the CAVE environment, telling them to look
around, look at the characters, and even wave at them if they felt like it. We basically asked
each participant to interact with the characters for 1 − 2 minutes in each mode and give us
their feedback. To do so, we asked them to evaluate the different modes by answering a set
of eight questions for each one:
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