Adam R. Richardson, David Waller
Human Factors: The Journal of the
Human Factor and Ergonomics Society
Summary
Virtual
environment enables the users to interact with spatial information in ways that
computer are not able to due to particular interface. VE applications appear to
be interesting for different applications, besides more practical and direct
applications it can be successfully implemented in researched in human
perception, cognition and social interaction.
There a big issue though
to be covered: the underestimation operators have of distance and the reasons
are still not fully understood.
Originally researches
suggested that the reason could be due to limited field of view, errors in
accommodation, lack of accurate binocular stereo images or limits in the
resolution and quality of the displays. Only recently Richardson and Waller
(2005) suggested that the underestimation may be not in the technology but in
the user himself, but they weren’t able to explain the reason and their method
appeared to be working only in repetitive tasks with feedback assistance.
The authors proposed 2
experiments, the first one in which participants estimated distances to virtual
targets before and after walking to various target in the VE, this had the aim
to test if there were improvements.
In the second experiment
the authors checked if the underestimating effect and the correction were
transferred to other means of estimating distances. The distance was measured
non verbally, asking the participants to walk while blindfolded to a previously
perceived target (this is a method often used in egocentric distance for this
kind of experiment since it minimize potential biases and higher level of
cognition strategies.
The apparatus was
providing a textured ground plane containing a target post place at different
distances, the environment was presented in Virtual Research V8 HMD with a
binocular stereo image of the scene (basically with one display per eye).
The fist experiment was
design with a pre-interaction (involving estimates of egocentric distance),
interaction (where participants walked towards the desired location) and
post-interaction (again test performed in the pre-interaction where carried
using different distances).
The experiment results
show that in VE distances are initially underestimated, but after practice in
the environment the user get more précises results (nearly fully correct).
The reason may lay in an
explicit strategy (for example the user may think of always walking further
than it really looks).
In experiment 2 the
subjects where asked to indicated distances in two ways: blindfolded directly
walking to the target and triangulation by walking (the observes first views
the target an the with no vision, traverses a path that is oblique to the
target, when instructed the observer turns to face the target and walks the
necessary steps.
The design of the
experiment again is in a similar manner of the experiment 1.
The results of the
experiment show that participant estimates’ of distance were formed with
respect to a percept of the target location that remained independent of the
method response, this is in contrast with Richardson and Waller (2005).
Key
Concepts
Virtual Environment,
Distance underestimation in virtual environments
Key Results
ANOVA results show how
implicit feedbacks also appear to be more precise than explicit ones in such an
environment, therefore it is believed that through training, the problem of
underestimation of the distance is not consistent, simple calibration is
required to enable the user to alter its perception in VE.
No comments:
Post a Comment