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Human Factors. in Virtual. Environments. Liz Bathrick Dr. Gallimore - HFE606 WSU - Fall 2002. What is a Virtual. Environment ?.
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Human Factors in Virtual Environments Liz Bathrick Dr. Gallimore - HFE606 WSU - Fall 2002
What is a Virtual Environment ? An artificial environment created with computer hardware and software and presented to the user in such a way that it appears and feels like a real environment. (webopedia) • Simple • Games - “Myst” • Web Portals • Complex • DMT • CAVE • Fully Immersive Bathrick, HFE 606 Fall 2002 - #2
What is a Virtual Environment ? Physical-Actual Collaborative Interactive Augmented Virtual Immersive Bathrick, HFE 606 Fall 2002 - #3
are Used for ... Virtual Environments • “Virtual Reality” Used & Abused (Games) • Relatively Expensive • Currently most true VEs are research or training oriented - • Military Training & Analysis • Institutional / Educational • Biomedical Research • Science & Engineering • Education & Training • Some entertainment venues (Disney, movies, games) Bathrick, HFE 606 Fall 2002 - #4
HFES VE Tech Group Interests • Human Performance & Efficiency • Health & Safety Problems • Potential Behavioral & Social Issues Bathrick, HFE 606 Fall 2002 - #5
HFES VE Tech Group Interests Specific Study Areas: • HMD ease of use & comfort in VEs • Human visual performance viewing Computer Generated VEs. • Tactile, haptic & force feedback • Design & evaluation of VE training systems. Bathrick, HFE 606 Fall 2002 - #6
Commentary from RPA HMD Designer/Developer • Discussion with Rotocraft Pilot’s Associate (RPA) HMD Designer - Reid Benes • Augmented Reality • A Keiser Optical Helmet • Full glass display • 3D Spatial audio • Design issues RPA HMD Bathrick, HFE 606 Fall 2002 - #7
Lessons Learned from RPA HMD Development Field of View (FOV) • As large as possible - slower update time, but subject will have stronger feeling of immersion • Display should closely match scene FOV • Large differences can lead to errors & difficulty in spatial judgements for depth & size of objects. • For augmented environments matching FOV is extremely important. e.g. Target acquistion overlay Bathrick, HFE 606 Fall 2002 - #8
Lessons Learned from RPA HMD Development Navigation • Walking while looking around in rich VE can cause more problems then moving straight ahead through an VE (like flying). • Speed of navigation in VEs can contribute to simulator sickness. Bathrick, HFE 606 Fall 2002 - #9
Lessons Learned from RPA HMD Development Color - Full color displays best Head Tracking - Very tricky • Can deter from the experience - esp. if yaw & roll are not well compensated for (3D head tracking) • Can be physically complicated if the user is moving around interacting in the VE - headtracking systems require close proximity to the sensors. Bathrick, HFE 606 Fall 2002 - #10
Lessons Learned from RPA HMD Development Stereoscopic View • Allows system to put information at different focal lengths for user to perceive 3D information - necessary for immersive systems. • Fixed focal length at infinity so user can see the outside world. • RPA looked at being able to display different types of information at different areas in the visual field & also at different focal lengths to reduce clutter and information overload. Bathrick, HFE 606 Fall 2002 - #11
Lessons Learned from RPA HMD Development System Trust - • Very important for applications trying to augment or model real world - e.g. surgical applications or flight decks. • Trusting VE too much when data isn't reliable can lead to errors or accidents. • Some current discussions about how to display error bars, or data reliability in the environment. Bathrick, HFE 606 Fall 2002 - #12
Helmet Mounted Displays (HMD) • Fixed Focus/Vergence & Line of Sight • Field of View - Diag, Vert, Horiz • Eyewear compatibility • Binocular Rivalry w/Monocular HMDs • Interpupilary Distance • Exit Pupil • Weight & Balance • Brightness & Contrast Ratio Bathrick, HFE 606 Fall 2002 - #13
HMDs & Virtual Simulation Sickness • “Cybersickness” vs. Motion sickness • User may not be actually moving • Effect may be residual after VE experience for hours or even days • Sensory Conflict Theory • Perceived cues don’t add up - see one thing, feel /hear another - • Usually visual & vestibular mismatch • Poison Theory • Body is physiologically fooled into reacting like it has been poisoned Bathrick, HFE 606 Fall 2002 - #14
HMDs & Virtual Simulation Sickness • Postural Instability Theory • Instability in the control of the posture of the body and/or its segments - Most predictive through vibration and oscillation experiments • Contributing Factors • System: Position tracking, lag, flicker, resolution • Subject: Age, gender, health, experience • Task: Scene content, movement quantity, control, & duration Bathrick, HFE 606 Fall 2002 - #15
Visual Performance in Computer Generated VEs • Largely related to HMDs • Synchronization of Visual, Audio & Haptic devices - lag time, logical movements, LOS • The basic question is: Will this system meet or exceed the visual requirements of the human user? Bathrick, HFE 606 Fall 2002 - #16
Movie file removed Bathrick, HFE 606 Fall 2002 - #17
& Force Feedback Tactile, Haptic • Gloves, Levitation Wands,Trackballs, Robotic Arms... • Degrees-of-freedom (DOF) • Spatial resolution • Resistance (isotonic vs isometric) • Body-centered interaction (“naturalness" of design and interaction) • Size, weight, comfort, mobility & portability • Mulitple users’ interactions Bathrick, HFE 606 Fall 2002 - #18
Design & Evaluation of VE Training Systems • How well people learn information is based on: • How information is presented • How students may interact with it while they are learning • Intentional Psychology: interaction techniques and biological constraints • Experiential Design: functionally aesthetic environments Bathrick, HFE 606 Fall 2002 - #19
Design & Evaluation of VE Training Systems • Situated Learning Theory (Intentional psychology) • Realistic task performance in authentic setting provides stronger context and application of learning objectives • Key components: Apprenticeship, Collaboration, Reflection, Coaching, Multiple practice, Articulation of learning skills, Realistic representations & technology • Cognitive Models (Experiential Design) • Artificial intelligence, agents • Can be represented by avatars or actors in VEs Bathrick, HFE 606 Fall 2002 - #20
Design & Evaluation of VE Training Systems • “Presence” - how immersed is subject? • Fidelity - how much is necessary? • Which factors produce correct transfer/coding • e.g. Military Flight Simulation • Part task trainers - Control systems • Full mission trainers - Tactical /Team ops • Trainee Decision-making in semi-realism • Compensations acquired in VE experience can negatively impact real-world performance Bathrick, HFE 606 Fall 2002 - #21
Social & Behavioral Problems in VE • Social Cognitive Theory • Arousal Theory - desensitization • Identity Construction Bathrick, HFE 606 Fall 2002 - #22
Social & Behavioral Problems in VE • Social Isolation • Impact on development of imaginative and creative skills • Group dynamics & social positioning • Communication feedback - gestures, reactions Bathrick, HFE 606 Fall 2002 - #23
Miscellaneous Other Things • Some real potential benefits to the physically or mentally challenged • Cool Education (as opposed to training) • Virtual Gorilla Exhibit Design - • Exploration of 15th C. Florence • Interaction with historical figures or characters in literature Bathrick, HFE 606 Fall 2002 - #24
Virtual Environments Summary of HF in VE Technical Group Interests • Human Performance & Efficiency • HMDs, Haptics, Training & Education • Health & Safety Problems • Simulator Sickness • Potential Behavioral & Social Issues Bathrick, HFE 606 Fall 2002 - #25
Some Final Thoughts • How much is too much? • Some things are really useful and others are just gimmicky. • Process of Discovery • With all this technology we need to make sure we don’t forget the human! Bathrick, HFE 606 Fall 2002 - #26
References & More Information • Benes, Reid. Personal Interview. November 15, 2002. • W. Bricken, G. Coco, "The VEOS Project", Technical report, Human Interface Technology Lab, University of Washington,(1993). • Gabbard, J., Hix, D. “Taxonomy of Usability Characteristics in Virtual Environments”. Final Report to the Office of Naval Research. (November 1997) • LaViola, Joseph J., Jr. “A Discussion of Cybersickness in Virtual Environments” SIGCHI Bulletin Volume 32, Number 1 (January 2000) • Stanney, Kay M. Handbook of Virtual Environments : Design, Implementation, and Applications Human Factors and Ergonomics. Mahwah, N.J. Lawrence Erlbaum Associates, Inc., 2002. • Chpater 3 - Vision and Virtual Environments • Chapter 24 - Spatial Orientation, Wayfinding,And Representation • Chapter 33 -The Social Impact of Virtual Environment Technology • Winn, William. “Learning in Interactive and Immersive Environments” Presented at the Conference "Media and Higher Education” National Institute for Multimedia Education Chiba, Japan,(November, 1995) Bathrick, HFE 606 Fall 2002 - #27
References & More Information • Cybersickness.org http://www.cybersickness.org/web_index.htm • Motion Sickness: Human And Medical Factors Index Page, Marbella 1997 http://www.ait.nrl.navy.mil/MSC/marbella_abstracts.htm#a11 • HFES VE Tech Group http://vered.rose.utoronto.ca/HFESVE.html • McLaughlin Consulting Group - “Human Factors Impact on Near-eye Design” http://www.mcgweb.com/reports/usdc_doe.htm • VISERG - Visual Ergonomics Research Group Loughborough University http://www.lboro.ac.uk/departments/hu/groups/viserg/viserg1.htm Bathrick, HFE 606 Fall 2002 - #28
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