Environmental Engineering Reference
In-Depth Information
• It allows teach a task under the approach of
learning by doing
, so the trainees can practice
the task as many time as needed to achieve the level of proficiency requested.
• It eliminates the constraints for using the real environment mainly: availability, safety,
time and costs constraints. For example, in medical domains there is no danger to the
patients, and little need for valuable elements such as cadavers or animals. Similarly
for aviation, there is no risk for the aircraft, nor fuel costs. In the case of maintenance
tasks, VR systems can offer a risk free environment for damaging machines of technicians
(Morgan et al. (2004); Sanderson et al. (2008)).
• It can provide extra cues, not available in the real world, and that can facilitate the
learning of the task. These cues can be based on visual, audio or/and haptic feedback.
A combination of these cues is called
multimodal feedback
2
. For example, to provide
information about the motion trajectory that users should follow, the system could
provide: visual aids (for example displaying the target trajectory on the virtual scenario) or
haptic aids (for example applying an extra force to constraint the motion of the user along
the target trajectory) or audio aids (for example sending a sound when the user leaves the
target trajectory).
• It allows simulating the task in a flexible way to adapt it to the need of trainees and the
training goal, for example removing some constraints of the task in order to emphasize
only key aspects.
• It can provide enjoyment, increasing the motivation of trainees (Scott (2005)).
• It allows logging the evolution of the trainees along the training process.
On the other hand, the greatest potential danger of the use of VR systems is that learners
become increasingly dependent on features of the system which may inhibit the ability to
perform the task in the absence of the features.
Developing dependence, or at least reliance, on VR features that do not exist in the real
environment or are very different from their real world counterparts can result in negative
transfer to the real world. If
fidelity
cannot be preserved or is hard to achieve, it is much
better to avoid the use of the VR instantiation, or alternatively, particular care must be taken
to develop a training program that identifies the VR-real world mismatch to the trainee
and provides compensatory training mechanisms. It may also be necessary to manipulate
the relational properties between feedbacks, i.e., the congruency between visual, audio, and
haptic stimulations, in order to favor cross-modal attention.
The experiment described in this chapter demonstrates that the controlled use of multimodal
feedback does not damage the trainee performance when the trainee changes from the VR
system to the real world and therefore it eliminates the main disadvantage of the use of VR
reported in the bibliography: the negative or no transfer.
2.2 Multimodal systems for training
Within the virtual reality systems we can find the multimodal systems. The term
multimodal
comes from the word multi that refers to
more than one
and the word modal that refers
to
the human sense that is used to perceive the information
, the sensory modality (Mayes
(1992)). Therefore, in this chapter a
multimodal system
is defined as a virtual reality system
that supports communication with the trainees through more than one sensory modality
(see Figure 1), mainly visual, haptic and auditory.
In order to support this multimodal
2
It refers to the use of different human sensory channels to provide information to users.
