Presence and Performance Within VEs
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Transcript of Presence and Performance Within VEs
Presence and Performance Within VEs
By Barfield, Zeltzer, Sheridan and Slater
Summarized by Geb Thomas
Topics
• Definitions
• Components of VE
• Measuring VE
Some Interesting Observations
• Attentional resources must be directed to the stimulus information for presence to occur
• Although a movie-goer might flinch, they may not feel “present”
• Two types of presence:– Observer is actually present one environment– Observer feels present in a different environment
Some Definitions
• Teleoperator - a machine that operates on its environment and is controlled by a human at a distance
• Teleoperator system includes both the operator and the machine -> teleoperator is the remote machine part of the system
Types of Teleoperators
• Manually controlled– Movements guided by the operator
• Master-slave teleoperator– Human positions the slave device, master
device follows
• Rate controlled teleoperator
Robot• From Karel Capek’s Play R.U.R. for Rossum’s
Universal Robots– performs functions ordinarily ascribed to human
beings, or operates with what appears to be almost human intelligence
• Robot Institute of America– reprogrammable multifunctional manipulator designed
to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks.
Supervisory Control• Supervising by:
– “specifying subgoals, constraints, criteria or procedures to a computer
– receiving back a variety of information about a telerobot’s state or performance, often in summary form”
• Machine must have some degree of intelligence• Often controlling a complex system in described as
supervisory control, even when it is strictly direct control.
Telepresence
• Human operator receives sufficient information about the teleoperator and the task environment, displayed in a sufficiently natural way, that the operator feels physically present at the remote site
• In space teleoperators it may mean equivalent to bare-handed operation.
Zeltzer’s AIP Cube• Autonomy
– act and react to simulated events and stimuli – 0 for passive, 1 for sophisticated agent
• Interaction– Software architecture for the HMI of the VE– 0 for batch processing, 1 for real-time access to all model
parameters
• Presence– number and fidelity of available sensory channels, task
dependant
Ellis’ Virtualization
• The process by which a human viewer interprets a patterned sensory impression to be an extended object in an environment other than that in which it physically exists
• Virtual space -- pictorial depth cues
• Virtual image -- accommodation, vergence, stereoscopic display
• Virtual Environment -- slaved motion parallax, depth of focus, wide FOV
Points on the Cube
• 0 0 0 - Models with no autonomy• 1 1 1 - perfect VE• 0 1 0 - commercial animation packages• 0 1 1 - interaction and presence • 0 0 1 - display systems• 1 0 1 - virtual Shakespeare• 1 0 0 - virtual movie?• 1 1 0 - complex autonomous, interactive scenes
Determinants of Presence
• Extent of sensory information (bits of relevant data)
• Control of sensors (navigation)
• Ability to modify the environment
• Lines of constant information depend unevenly on the different parameters
Subjective Measures
• A multi-dimensional rating scale, such as NASA-TLX scale
Physiological Measures
• Things you can measure: heart rate, blood pressure, respiratory rate, electric brain potentials, muscle activity, visual acuity, blink rate, hearing acuity, catecholamines
• For VE, we might investigate:– Pupillary responses, amplitude and duration
depends on workload– Evoked brain potential, P300 depends on
workload.