Exam 2 Review Flashcards
VR sickness
Symptoms similar to those of motion sickness due to a VR experience
List the symptoms of VR sickness
headaches stomach awareness nausea vomiting pallor sweating fatigue drowsiness disorientation
What should be done to reduce VR sickness?
Reduce the FOV
What should be done with the FOV?
Dynamically adjusted depending on virtual movement
What data was collected during the FOV on VR sickness experiment?
Discomfort scores every five waypoints
Was it found that decreasing the FOV affected the presence?
No
T/F Distance and size perception are often biased in VR
T
What were the three settings used in distance estimation?
Negative parallax
Zero parallax
Positive parallax
Define: Negative parallax
Virtual object is rendered in front of physical display
Define: Zero parallax
Virtual object is rendered at the physical display
Define: Positive parallax
Virtual object is rendered behind the physical display
What task was used in the distance estimation experiment?
A blind triangulation pointing task
What was the finding of the distance estimation experiment?
Increased distance underestimation for positive parallax conditions
What was the pointing task procedure?
Viewed a target’s position
Virtual view was blinded by pressing a button
Participants would take two steps left or right
Then point at the target as accurately as possible
T/F Most users experience some imbalance in VR
T
What did the imbalance experiment investigate?
how a static rest frame (SRF) affects balance in an HMD
Define: static rest frame
A cross-hair always rendered in the same position on the user’s display screen
What task were the participants asked to do in the balance impairment study?
Dodge tennis balls
What did the balance impairment study conclude?
An SRF significantly improves balance for users with balance impairments
What was investigated in the body ownership experiment?
Investigated the effects of visual realism of virtual hand representations
What is low realism?
Abstract (sphere)
What is medium realism?
Iconic (skeleton hand)
What is high realism?
Human (actual hand model)
What task would you use in a body ownership study?
Pick-and-place and spinning saw tasks
What could be concluded from a study on body ownership about the sense of agency?
Found sense of agency (i.e., motor activity control) to be greater for less realistic hands
What could be concluded from a study on body ownership about the sense of ownership?
Found sense of ownership (i.e., one’s own body is the source of sensations) to be greater for the human hand
What was investigated in the virtual human study?
Investigated the effects of a shared real-virtual object (a wobbly table) on presence and social presence
Define: Social presence
Sense of being socially connected with another person
What were participants asked to do during the virtual human study?
Play a game of twenty questions with a virtual human
What were the results of the virtual human study?
Found that the wobbly table condition resulted in greater presence and social presence
What was investigated in the collaborative environments study?
Investigated the effects of including virtual objects within a mixed reality (MR) environment on deictic speech
Define: Deictic speech
Spatial indications that cannot be fully understood by speech alone
What tasks did participants in the collaborative environments study do?
Dyads of participants completed object identification and object positioning tasks
In the collaborative environments study, what were the findings?
Found that the inclusion of virtual environment objects decreased deictic speech for both tasks
What was done in the AR study?
Compared two augmented reality (AR) visualization techniques for assembly guidance
What else was investigated in the AR study?
Also investigated the effects of error detection
What were the findings of the AR study?
Found that the side-by-side mode resulted in faster completion times and fewer errors
Define: Independent variable
A variable that is manipulated and controlled by the researcher to help answer the research questions
What is an independent variable also know as?
Factor
T/F All studies have an independent variable
F
What kind of study does not have an independent variable
A baseline study observing a single user interface
Define: levels
The distinct states that an independent variable is controlled at
Define: multi-factor experiment
An experiment that simultaneously investigates multiple independent variables at multiple levels
Define: Condition
The intersection of independent variables at specific levels
Define: dependent variable
A measure that is expected to vary with changes to the independent variables
List examples of dependent variables
Completion time
Number of errors
Perceived usability
Presence
Define: confounding variable
An unintended variable that correlates with both the independent variables and the dependent variables
What is a confounding variable also known as?
Confound
Give an example of a confounding variable
Airflow in an olfactory display study
What are the three primary types of user studies?
Within-subject
Between-subjects
Mixed-design
Define: Within-subject
Every single subject experiences every single condition
Define: Between-subjects
Each subject experiences one condition
Define: Mixed-design
Each subject experiences multiple conditions but not every single condition
What are the pros of within-subject?
Requires the fewest subjects
Allows for direct subjective comparisons
What are the cons of within-subject?
Requires the longest procedures
Cannot be used to evaluate the effectiveness of instruction
What are the pros of between-subjects?
Requires the shortest procedures
Can be used to evaluate the effectiveness of instruction
What are the cons of between-subjects?
Requires the most subjects
Does not allow for direct subjective comparisons
Results prone to being biased by subjects
What are the pros of mixed-design?
Requires fewer subjects
Requires shorter procedures
Allows for some direct subjective comparisons
What are the cons of mixed-design?
Cannot be used to evaluate the effectiveness of instruction
T/F The order of conditions can influence results
T
What is an example of the order of conditions influencing results?
Learning a task improves performance regardless of interaction technique
Define: counterbalancing
Ensuring the order of conditions is balanced among subjects
List the methods of counterbalancing
Full-factorial permutations of conditions
Latin squares designs
T/F Participants cannot bias cohort results
F. they can
List unbiased assignments methods
Randomization
Aptitude balancing
What is randomization?
Randomly assign subjects to available cohort slots
What’s the downside of randomization?
Requires a decent number of subjects to avoid bias
What is aptitude balancing?
Assign subjects to available cohort slots to balance aptitude and/or experience across all cohorts
What does an aptitude balance require?
Requires a validated aptitude test or experience survey
If your participants are expected to have balance impairments, what can you implement to help them?
A static rest frame (SRF)
What was used in the virtual human study to try and improve presence and social presence?
A wobbly table
