Transcript Chapter.7 - VR Technology

Electrical and Computer Engineering Dept.
Human Factors in VR
User
(programmer,
trainee, etc.)
System architecture
Human factors in VR
Human
Performance
Efficiency
Societal
Implications
Health
and
Safety
(Stanney et al., 1998)
Human factors in VR
Will the user get sick in VR?
Which tasks are most suitable
for users in VR?
Which user characteristics
will influence VR performance?
Will there be negative societal
impact from user’s misuse of
the technology?
How should VR technology
be improved to better meet
the user’s needs?
?
How much feedback from VR
can the user process?
Will the user perceive
system limitations?
What kind of designs will
enhance user’s performance
in VR?
(Stanney et al., 1998)
Human factors vocabulary
 HF study – series of experiments in very rigorous conditions
aimed at the user (can be controlled or case study);
 Experimental protocol – establishes a structured sequence of
experiments that all participants need to perform;
 Trial – a single instance of the experiment;
 Session - a sequence of repeated trials;
 Rest period – time between sessions;
 Experimental database – files that store experimental data;
 Institutional Review Board (IRB) – watchdog office regulating HF
experiments
 Principal Investigator (PI) – person conducting the HF study.
Needs to be certified by the IRB
H. F. vocabulary - continued
Subject - a participant in a HF study (male or female, age, volunteer
or paid, right handed or left handed, normal or disabled, etc);
 Experimental group – subjects on which the experiments are done;
 Control group – a number of subjects used for comparison with the
experimental group;
 Controlled study – a study that uses both an experimental and control
group
 Case study (also called pilot study) – smaller study with no control
group.
Feasibility Study – look at technology acceptance and effect
Consent form – needs to be signed by all participants into the study;
Baseline test – measurement of subject’s abilities before trial;

Human factors in VR
Human
Performance
Efficiency
Societal
Implications
Health
and
Safety
(Stanney et al., 1998)
Determine
focus
Develop experim.
protocol
The stages of
human factors
studies
Recruit
subjects
Conduct study
Analyze data
Determine focus
The stages of
human factors
studies
Develop experim.
protocol
Recruit subjects
Conduct study
Analyze data
Human factors focus
 What is the problem? (ex. People get headaches)
 Determines the hypothesis (ex. Faster graphics is
better);
 Establishes type of study (usability, sociological,
etc.);
 Objective evaluation, subjective evaluation or
both?
…
Determine focus
The stages of
human factors
studies
Develop
experimental
protocol
Recruit subjects
Conduct study
Analyze data
Experimental protocol
 What tasks are done during one trial?
 How many trials are repeated per session?
 How many sessions per day, and how many days
for the study?
 How many subjects in experimental and control
group?
 What pre and post-trial measurements are done?
 What variables are stored in the database?
 What questions on the subjective evaluation
form?
Determine focus
The stages of
human factors
studies
Develop experim.
protocol
Recruit subjects
Conduct study
Analyze data
Subject recruitment
 Sufficient number of subjects need to be enlisted
in the study to have statistical significance;
 Place advertisements, send targeted emails, web
posting, go to support/focus groups, friends, etc.;
 Subjects are screened for unsuitability to study;
 Subjects sign consent form;
 Subjects are assigned a code to protect their
identity;
 Subjects sign release for use of data in research,
Subjects may get “exposure” to technology;
Determine focus
The stages of
human factors
studies
Develop experim.
protocol
Recruit subjects
Conduct study
Analyze data
Determine focus
The stages of
human factors
studies
Develop experim.
protocol
Recruit subjects
Conduct study
Analyze data
Data Collection
 VR can sample much larger quantity of data and at
higher temporal density than classical paper-and-pencil
methods;
 Data recorded online can be played back during task
debriefing and researchers do not have to be co-located
with the subjects (remote measurements);
 Measurements need to be sensitive (to distinguish
between novice and expert users), reliable (repeatable and
consistent) and valid (truthful);
 Latencies and sensor noise adversely affect these
requirements.
Data Analysis
 Experiments store different variables, depending
on the type of test:
task completion time – time needed to finish the task (can
use system time, sequence of actions, or stopwatch);
 task error rate – number or percentage of errors done
during a trial;
 task learning – a decrease in error rate, or completion
time over a series of trials;
 Analysis of Variation (ANOVA) – statistical package
used to analyze data and determine if statistical difference
exists between trials or conditions.

Data analysis - continued
Error rates
Standard deviation
Average
Task learning
1
2
3
Trial number
Learning results in less errors and more uniform
performance among subjects
Data analysis - continued
Group C (very difficult task)
Error rates
Group A
Group B (very easy task)
1
2
3
Trial number
Effect of prior knowledge on task learning
Data analysis - continued
Monoscopic Group, small fps,
high fps variability
Error rates or
completion time
Stereoscopic Group
High fps, small variability in fps
N
H
H-A
Feedback modality
Data analysis - continued
Task learning time and error rates are applicable to VR in
general;
Performance measures which are modality specific – for
example for force feedback - Average contact force – the
forcefulness of the interaction with a virtual object
N
∑i=1 fi
Average force =________
N
where N is the number of data samples
and fi is the magnitude of the i-th force
Data analysis - continued
Another modality-specific performance measure is the
cumulative contact force. Higher cumulative forces/torques
indicate higher subject’s muscle exertion
 This can lead to muscle fatigue of haptic interface
premature wear.
N
Cumulative force = ∑i=1 fi Xt
Where t is the sampling interval
 There are also task-specific performance measures, such as
those associated with cognitive tasks (heart rate, muscle tone,
skin conduction, breathing rate, etc.)
Usability Engineering
 A subclass of human factors research to determine the
ease (or difficulty) of use of a given product;
 It differs from general-purpose VR human factors studies
which are more theoretical in nature;
 Usability studies are product-oriented and part of the
product development cycle.
 There are no clear standards, because this is an area of
active research.
Usability Engineering
The methodology consists of four stages:
User task analysis
Expert guidelinesbased
evaluation
Formative
Usability
evaluation
Summative
evaluation
“Sea Dragon” military command and control application
Usability Engineering
The first stage – define the task and list user’s
actions and system resources needed to do it;
User task analysis
 Identifies the interrelationships (dependencies
and order sequences) and user information flow
during the task;
 Poor task analysis is a frequent cause of bad
product design.
 For Dragon, the task is 3-D navigation and
object (symbol) selection and manipulation.
 it differs from classical 2-D maps and
symbols.
Expert guidelinesbased
evaluation
Formative
Usability
evaluation
Summative
evaluation
Usability Engineering
The second stage (sometimes called heuristic
evaluation) aims at identifying potential usability
User task analysis
problems early in the design cycle.
 A pencil-and-paper comparison of user’s
actions done by experts, first alone, and then as a
group (to determine consensus);
 For Dragon, ease of navigation was identified
as a critical issue; experts identified problems
with the system responsiveness, when using a
flight stick (wand with buttons) and performing
“exocentric” navigation (the user was outside of
the environment, looking in).
Expert guidelinesbased
evaluation
Formative
Usability
evaluation
Summative
evaluation
The third stage is an iterative process where
representative users are asked to perform the
task;
 During task performance variour variables
are measured, such as task completion time and
error rates. These are used to do product redesign and the process is repeated;
 Dragon formative evaluation had two stages.
During the first stage the best interface was
selected between three candidates (PinchGlove,
voice recognition and wand). Voice recognition
was ineffective, and PinchGlove produced time
delays when transferring to another user. Thus
wand was selected.
Usability
Engineering
User task analysis
Expert guidelinesbased
evaluation
Formative
Usability
evaluation
Summative
evaluation
The second stage of Dragon formative
evaluation used a large number of subjects that
had to navigate, while errors were recorded.
 A large effort was made in mapping the
wand button to functions. Pan and zoom were
mapped to the wand trigger, pitch and heading
to the left button, while exocentric rotate and
zoom were mapped to the right button
Usability
Engineering
User task analysis
Expert guidelinesbased
evaluation
Formative
Usability
evaluation
Summative
evaluation
Usability Engineering
The last stage is Summative evaluation which is
done at the end of product development cycle. It
is done to statistically compare the new product User task analysis
with other (competing) products to determine
which is better. The selection among several
Expert guidelinescandidates is done based on field trials and expert
based
reviews.
evaluation
 The summative evaluation of Dragon involved
the study of four parameters: navigation metaphor
(egocentric or exocentric), gesture mapping (rate
or position control of camera), display device
(workbench, desktop, wall or CAVE) and
graphics mode (stereo or mono)
Formative
Usability
evaluation
Summative
evaluation
Usability Engineering
 The summative evaluation of Dragon involved thirty two subjects
divided in groups of four. Each group was assigned a different
combination of conditions.
Usability Engineering
Results showed that users:
o performed fastest on a desktop monitor;
o were slowest on the workbench.
o Egocentric navigation was fastest in monoscopic graphics
o Exocentric navigation was fastest in stereo graphics.
o Rate control was fastest in monoscopic graphics;
o Position was fastest for stereo graphics.
Testbed Evaluation of Universal VR Tasks
 Testbeds are a way to deal with evaluation complexities.
 They are composed of a small number of “universal” tasks such
as travel in a virtual environment, object selection and object
manipulation;
 Provide a structured way to model subject performance, although
the evaluation is more expensive to do.
 Testbeds make possible to predict subject’s performance in
applications that include the tasks, sub-tasks and interaction
techniques they use.
Testbed Evaluation of Universal VR Tasks - continued
 Testbed evaluation of navigation tasks: obstacles (trees and fences)
and targets (flags) can be randomly placed.
 There were 38 subjects divided in 7 groups, each using a different
Navigation technique (steering based, manipulation-based and target
specification techniques)
Testbed Evaluation of Universal VR Tasks - continued
 Steering-based: Pointing, gaze tracking or torso tracking;
 Manipulation-based: HOMER or Go-Go; In go-go the subject
stretches his hand into the virtual world, grasps an object and then
pulls the virtual camera forward;
 Target-specification: ray casting or dragging.
 Fastest – gaze-directed (but produced eye strain and nausea)
Testbed Evaluation of Universal VR Tasks - continued
 Testbeds used for object selection and placement tasks;
 Subjects had to select a highlighted cube and place it in a target
area (between the two gray cubes);
Testbed Evaluation of Universal VR Tasks - continued
 There were 48 subjects divided among 9 groups. Object selection
was done either by ray casting or occlusion. Scene was seen on HMD;
 For each subject the distance to the object, the DOF used for box
Manipulation (2 or 6) or ratio of object/target size (1.5x, 3.75x) varied.
 Distant objects were harder to select, Go-Go was slowest mode.
Influence of System Responsiveness on User Performance
 System responsiveness inverse proportional to the time between
user input and the simulation response to that input.
HF studies done at Rutgers in early 90s to determine influence of
refresh rate (fps) and graphics mode (mono/stereo) on tracking
task performance in VR;
Subjects were 48 male and 48 female (volunteer undergrad
students), right handed. Task was the capture of a bouncing ball in
the smallest amount of time;
 Subjects were divided in sub-groups, each having a different
refresh rate, and graphics mode;
 Each subject performed 12 trials separated by 15 seconds rest
periods;
Ball appeared with random velocity direction and maintained a
speed of 25 cm/sec
Influence of System Responsiveness on User Performance
Influence of System Responsiveness on User Performance
 Ball capturing time was influence sharply by the graphics
refresh rate, especially when the rate fell below 14 fps;
 The standard deviation grew with the decrease in fps, indicating
less uniformity among the subjects in the experimental groups;
 Stereo made a big difference for low refresh rates, where task
completion time was approximately 50% of the time taken to
complete the task under monoscopic graphics;
 the subjects had different strategies for grasping the ball
At low refresh rates, where the ball motion appeared saccadic,
they grasped in a corner, keeping their arm stationary,
At high refresh rates they moved theirs hand in a ballistic way to
capture it.
Mean completion time (sec)
Influence of System Responsiveness on User Performance
Mono graphics
Stereo graphics
Frames per second (fps)
Effect of frame rate and graphics mode on task
completion time (Richard et al., 1995)
Influence of System Responsiveness on User Learning
 The frame refresh rate had a significan influence on the way
subjects learned;
 The group with highest task learning was that corresponding to
monoscopic graphics displayed at 1 fps.
completion time (sec)
Mono graphics
Trial number
Influence of System Responsiveness on User Learning
The least learning was for the groups with high refresh rates (14
fps and 28 fps). Their curves were almost flat;
 Stereo had a beneficial effect on learning (subjects were more
familiar to the task – it was presented more realistically to them).
completion time (sec)
Stereo graphics
Trial number
Influence of System Responsiveness on Object Placement tasks
Watson performed a test to determine the influence of
system responsiveness and its variability (expresses as
Standard Deviation of System Responsiveness) on object
placement tasks.
 The task was to capture an object and place it on a
pedestal, while receiving monoscopic graphics feedback;
 System responsiveness was altered by changing the
frame refresh rates to 17fps, 25fps and 33 fps. For each
frame rate, the SDSR was changed from 5.6%, 22.2%
and 44.4%;
Influence of System Responsiveness on Object Placement tasks
Results showed that subject performance (expressed as
placement time and accuracy) was effected by both SR
and SDSR.
 The variability in system responsiveness had the
largest influence on placement tasks done at low refresh
rates. The worst was placement done at 17 fps, with
44.4% SDSR.
 When done at 33 fps and 5.6% SDSR accuracy
improved 90%.
Influence of System Responsiveness on Object Placement tasks
Influence of Feedback Multi-modality
 HF studies done at University of Birmingham in late 90s to
determine influence of force feedback mode on task completion
time in VR;
 Task was the manipulation of disks to construct the “Tower of
Hanoi”.
 Four conditions – non-immersive VR with 2-D mouse, immersive
(HMD) with 3-D mouse, immersive with instrumented objects, and
real objects;
 Use of “instrumented objects” (disks with a tracker attached) to
provide force feedback – augmented VR
 Subjects were four male with six-months experience in VR each;
 Each subject performed 10 trials for each condition, conditions
were randomized.
Influence of Feedback Multi-modality
Problem –
Stack three rings
on another pole;
Larger ring never
on top of smaller one
1
2
3
5
6
Tower of Hanoi task
4
7
Influence of Feedback Multi-modality
experimental setup (IO condition)
3-D manipulation task –
Tower of Hanoi
Virtual scene during experiments
(Boud et al., 2000)
Task completion time (sec)
Influence of Feedback Multi-modality
Tower of Hanoi
performance
experimental condition
(Boud et al., 2000)
Influence of sensorial redundancy and substitution
Definition
Sensorial substitution (or transposition) occurs whenever information
that is usually in one sensorial domain is presented to the brain
through another sensory system.
Sensorial redundancy involves the use of several (at least two)
sensorial domains to present the same information to the subject.
Influence of sensorial redundancy and substitution
 HF studies done at Rutgers in mid 90s to determine influence of
force feedback mode on task performance in VR;
 Task was the manipulation a deformable virtual ball on a
prescribed path, in shortest time;
 Ball needed to be deformed 10% of radius or less;
 Subjects were male and female (volunteer undergrad students),
right handed, and none had seen the system before;
 Subjects were divided in sub-groups, each having a different force
feedback modality and graphics mode;
 Frame rate was maintained at 28 fps;
 Each subject performed 12 trials separated by 15 seconds rest
periods;
Influence of sensorial redundancy and substitution
3-D capturing and manipulation task setup
Influence of sensorial redundancy and substitution
Sensorial substitution
Mean object deformation (%)
Influence of sensorial redundancy and substitution
RMI
RMII
3-D manipulation task
Force Feedback Modality
Effect of interface dynamic range on
task performance (Fabiani et al., 1996)
Sensorial Illusion
 This happens during cross-modal “enhancement” – when weak
haptic feedback is supplemented by another modality. Example –
Biocca’s study found that 30% of subjects reported feeling the
weight and inertia of virtual objects when interacting with
PinchGloves
Sensorial Illusion
 Another form of sensorial illusion is provision of haptic texture
feedback through vision
 By manipulating the gain in mouse arrow movement in response
to user real movement it is possible to simulate bumps and valleys
in the object surface
Supplemental
video
Download and experience these textures from
http://www.irisa.fr/tactiles/index-eng.html
Sensorial Conflict
 Another form of sensorial illusion in sensorial conflict in which
information from one sensorial channel contradicts that received by
another sensorial channel.
 An extreme case of sensorial conflict is simulation sickness
which will be discussed later.
 French researchers studied the “boundary of illusion” between
conflicting visual and haptic feedback.
VC 7.1
Human factors in VR
Human
Performance
Efficiency
Societal
Implications
Health
and
Safety
(Stanney et al., 1998)
Effects of VR Simulations on users
The effects VR simulations have on users can be classified as direct
and indirect;
Definitions
Direct effects involve energy transfer at the tissue level and are
potentially hazardous;
Indirect effects are neurological, psychological, sociological,or
cybersickness and affect the user at a higher functional level.
Direct Effects of VR Simulations on Users
 Affect mainly the user’s visual system, but also the auditory, skin
and musculoskeletal systems;
 Effects on the skin and muscles are due to haptic feedback at too
high a level.
The intensity of Wii game playing can lead to injury. Statistics
posted on http://www.wiihaveaproblem.com/damage.php
Direct Effects of VR Simulations on Users
Effects on the visual system occur when the user is subjected to
high-intensity lights directed at his eyes (like Lasers used in retinal
displays (if they malfunction), or IR LEDs as part of eye tracking
systems;
 An “absence” state can be induced in a user subjected to pulsing
lights at low frequency (1-10 Hz);
 Bright lights coupled with loud pulsing sounds can induce
migraines (20% of women and 10% of men are prone to migraines.
 Direct effects on the auditory system are due to simulation noise
that has too high a level (115 dB after more than 15 minutes);
Cyber sickness
 User safety concerns relate primarily to cyber sickness, but also to
body harm when haptic feedback is provided;
 Cyber sickness is a form of motion sickness present when users
interact with virtual environments;
 Cyber sickness has three forms:
 Nausea and (in severe cases) vomiting;
 Eye strain (Oculomotor disturbances);
 Disorientation, postural instability (ataxia) and vertigo.
 Flight simulators have an incidence of up to 60% of users
experiencing simulation sickness (military pilots – elite group);
 Studies suggest regular VR users are affected more (up to 95%)
(Stanney and Hash, 1998)
Cyber sickness Model
 Since many users are affected, it is important to study cyber
sickness, in order to reduce its effects, and allow wide-spread use of
VR;
 Few studies exist. Based on these the following model was
developed:
Prior
Experience
Human
Body
Neural
Conflict
Adaptation
Virtual
Environment
Simulation
sickness
Aftereffects
The Cyber sickness model
Prior
Experience
Human
Body
Neural
Conflict
Adaptation
Virtual
Environment
Simulation
sickness
After-effects
System characteristics influencing cyber sickness
 When VR technology has problems, it can induce simulation
sickness. Example:
- Tracker errors that induce a miss-match between user motion and
avatar motion in VR;
- System lag that produces large time delays between user motion
and simulation (graphics) response. Lag is in turn influenced by
tracking sampling speed, computer power, communication speed,
and software optimization.
- HMD image resolution and field of view. Poor resolution and
small FOV are not acceptable. Large FOVs can also be problematic.
Influence of user’s characteristics on cyber sickness
 The user characteristics can play an important role in cyber
sickness:
- Age that induce a miss-match between user motion and avatar
motion in VR;
- Health status. Sick users, including those that take medication or
drugs are more prone to cyber sickness.
- Pregnancy. Female users who are pregnant are more prone to
simulation sickness.
- Susceptibility to motion sickness. Some people are more prone to
motion sickness than others. Pilots are screened for such.
The Cyber sickness model
Prior
Experience
Neural
Conflict
Adaptation
Virtual
Environment
Human
Body
Degree of
Interactivity
Simulation
sickness
After-effects
Influence of user’s degree of interactivity on cyber sickness
 HF studies done at University of Central Florida (Stanney and
Hash, 1998) to determine influence of user degree of control on
cyber sickness in VR;
 Task was 3-D navigation in a maze (shown below):
3-D navigation task (Stanney and Hash, 1988)
Influence of user’s degree of interactivity on cyber sickness
 There were three control conditions:
Passive control – users were “taken on a ride” on a preprogrammed
path, and had no input to the simulation;
 Active control – users navigated using a joystick with 6 DOF;
 Combined active-passive control – users navigated using the same
joystick, but with some degrees of freedom disabled, based on taskspecific motions (doors, windows, elevators);
 There were eight subjects in each experimental group (24 total, both
male and female); They each performed the task for 30 minutes;
 The virtual environment was displayed on a PC in stereo, so subjects
wore stereo glasses.
 Results showed that active-passive control reduced significantly
cyber sickness effects. Passive control did worse.

3-D navigation task (Stanney and Hash, 1988)
Influence of user’s degree of interactivity on cyber sickness
control is better than active control, because
unnecessary motions are eliminated, thus reducing the amount of
neural conflicts. Both reduce adaptation time.
 Simulation sickness was self-reported by subjects using a
Simulation Sickness Questionnaire (SSQ)
Passive Control
SSQ Score
 Active-passive
Active Control
Active-Passive Control
Nausea
Oculomotor
Disorientation
Total severity
distortion
3-D navigation statistics (Stanney and Hash, 1988)
The Cyber sickness model
Prior
Experience
Human
Body
Neural
Conflict
Adaptation
Virtual
Environment
Simulation
sickness
After-effects
Neural Conflict
 Occurs when simulation and body sensorial feedbacks conflict;
The conflict (sensorial rearrangements) can be of three types:
 Type I: two simultaneous conflicting signals (A and B) – example
Information from a moving platform does not coincide with the
motion of waves seen on an HMD.
 Type II: Signal A is present and B is not – example looking at a
roller coaster simulation, without a motion platform;
 Type III: Signal B is present and signal A is not – flight simulation
in fog (instrumented flight). Motion platform moves, but visual
feedback is unchanged.
 Since more information from the simulation results in more
conflict, it is logical that neural conflict induced cyber sickness
grows with the duration of immersion in the VE.

Influence of exposure duration on cyber sickness
 HF studies done at University of Central Florida (Kennedy et al.,
2000) to determine influence of simulation duration on cyber
sickness;
 Task was flying a helicopter, and subjects were military pilots;
 The data was divided according to duration in:
 Simulation session of 1 hour or less;
 1 to 2 hours;
 2 to 3 hours;
 Simulation session of over three hours
 It showed that there is a linear relationship between duration of
simulation and the degree of simulation sickness; Thus the duration
of initial exposure should be limited, to minimize discomfort;
Average Total Sickness Score
Influence of simulation duration on cyber sickness
Flight Session Duration (in hours) (Kennedy et al., 2000)
The Cyber sickness model
Prior
Experience
Human
Body
Neural
Conflict
Adaptation
Virtual
Environment
Simulation
sickness
After-effects
Influence of repeated exposure on cyber sickness
HF studies done at University of Central Florida
(Kennedy et al., 2000) to determine influence of user
adaptation on cyber sickness;
 Since prior neural images play such an important role in
cyber sickness, can repeated exposure to VR desensitize
the user?
 Study looked at military helicopter simulators, thus
subjects were pilots, and task was prone to induce sickness
(violent maneuvers).

Influence of repeated exposure on cyber sickness
The
study used a “Total Sickness Score” with a 35% as
zero-point. Thus for military pilots 35% incidence of
simulator sickness is considered acceptable. For the general
public it is not.
 Results showed a significant reduction in TSS after a
few flights showing that the subject had adapted to the
neural mismatch. While mismatches exist, there are
considered as matches due to prior experience.
Influence of repeated exposure - results
Average Total Sickness Score
 The study did not indicate how long the subsequent exposures
should be, nor over what time interval they should take place. It is
believed that no more than one week should separate simulation
sessions.
Flight Number
Cyber sickness scores vs. number of successive
flights (Kennedy et al., 2000)
Adaptation
Definition
“Adaptation to sensory rearrangement is a semi-permanent change of
perception and/or perceptual-motor coordination that serves to reduce
or eliminate a registered discrepancy between, or within, sensory
modalities, or the errors in behavior induced by this discrepancy.”
Hand-eye coordination adaptation [Groen and Werkhoven 1998].
a) before VR
exposure
b) initial mapping
through artificial offset
c) adapted
grasping
d) aftereffects
The Cyber sickness model
Prior
Experience
Human
Body
Neural
Conflict
Adaptation
Virtual
Environment
Simulation
sickness
Aftereffects
Aftereffects
Induced through adaptation to neural conflicts.
 Occur after the simulation session ended and can last for
hours or days;
 While adaptation is good, aftereffects may be bad. Forms
of aftereffects are:
 Flashbacks;
 Sensation of “self motion”;

Aftereffects
Headache
and head spinning;
 Diminished (remapped) hand-eye coordination;
 Vestibular disturbances;
 These aftereffects lead Navy and Marines to institute
grounding policies after simulator flights. Other bans may
be necessary (example driving, biking, roof repair,
operating machinery, etc.).
Guidelines for Proper VR Usage
Meant to minimize the onset and severity of cybersickness. They
are largely qualitative
Guidelines for Proper VR Usage
Human factors in VR
Human
Performance
Efficiency
Societal
Implications
Health
and
Safety
(Stanney et al., 1998)
Social implications of VR
 Violence of VR games are a concern, as additive
response could result. Violence may also induce
desensitization to real-world violence. This may be another
negative “after-effect” of VR.
 Another social impact may be increased individual
isolation, through reduced societal direct interaction and
involvement. Avatar-mediated interaction, while allowing
sharing of virtual worlds may not be a substitute to direct
human-human interaction.
Social implications of VR
Second Life Online Society People become members, then can build
communities or islands, buy at virtual stores and play games. “An
online 3D virtual world imagined and created by its Residents
http://secondlife.com
Create content
Second Life Online Society
Socialize
Events/Games
Social implications of VR
Synthetic and distance learning using VR may not
adequately replace direct student-professor interaction.
Reduction in education quality may result;
 Reduction in health-care quality may also be present –
especially for mental health and at-home rehabilitation.
However for seniors VR reduces the sense of isolation
and
 Can be used in “brain” training.
Mental rehabilitation VR systems
One form of game-based mental training is the Nintendo DS
and Nintendo DS Lite
It allows seniors to have fun while playing mind-challenging
games, using a stylus and voice input
Brain Age 2 has100 activities designed to help work your
brain and increase blood flow to the prefrontal cortex.
Mental rehabilitation VR systems
 When starting a new game, you will take a series of tests that
show how old your brain is (“Brain Age”).
With daily training over weeks and months, you can improve your
mental acuity and lower your Brain Age.
Can compete against others
Online Cognitive Rehabilitation
The Lumosity Co. (lumosity.com) allows
subscription ($10/month) to video games that train
the attention, memory, cognitive control and
processing speed with against-the-clock games.
After 30 sessions subjects that played the games
also improved in independent tests of memory.
The dangers of video games (general)
Excessive game play can be fatal. In Korea, where 30% of the
population subscribes to online multiplayer games, one man died in
2005 after playing 50 hours (almost non-stop) StarCraft. 3 Chinese
died in 2007 after playing more than 50 hours, and 2 died in 2005.
EverQuest is a 3D online game played by more than 400,000 people;
Games can lead to isolation, and suicide. Hudson Wooley, an epileptic
who was playing 12-hours per day, eventually committed suicide.