1. CS260 Lecture 7
Professor John Canny
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2. Computer-Mediated Communication
Communication involves at least two people. What are their respective goals?
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3. Electronic Media vs. Face-to-face
Knowledge workers have a host of electronic media available, but still travel across town or across the country for face-to-face meetings.
Why?
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4. High-stakes communication
What were the most important communications you have had in the last several years?
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5. Media richness (Daft & Lengel)
Match the affordances of the medium to the communication task.
High richness (often high stakes)
Face-to-Face
Ambiguity, ephemeral,
expressive
Video-conf?
Telephony IM
Clarity, recording,
constraint
/memos
Reports
Low richness
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6. Media choices in the workplace
For routine business communication, we surveyed users about their choice of media:
Instant Messaging
Telephony
Face-to-face
There was one medium that rated higher under several criteria. What do you think it was?
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7. Non-verbal communication
In real life, we use a lot more than speech (or sign language) to communicate.
Non-verbal communication includes:
Gaze, eye contact
Facial expression
Gesture
Posture
Touch
Location (proxemics)
Time
Prosody (speech)
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8. Non-verbal communication
Which of these cues are preserved by: ?
Instant messaging?
Telephony?
Video-conferencing?
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9. Non-verbal communication
Q: What is the role of these cues in normal communication?
A: It depends totally on the role of the communication, e.g.
Routine (giving information, coordinating)
Persuading and being persuaded
Trust, deception and negotiation …
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10. Routine communication
Most of what happens in most organizations.
Doesn’t seem to benefit much from non-verbal cues, and in fact there is evidence that people prefer less-rich media such as and telephone:
Sproull and Kiesler: computer science students did better with than face-to-face meetings.
Connell et al.: Business employees preferred the phone over face-to-face and for routine communication.
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11. Persuasion
Seems to be strongly influenced by gaze and facial cues (Werkoven et al.).
Note: Most non-verbal cues are not consciously processed. We transmit and receive without being aware of what we are doing. Most non-verbal cues are strongly influenced by our personality and emotional state.
Facial expression is different however. We consciously manage it, and it shows very little correlation with emotional state.
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12. Trust and deception
Most people emit easy-to-read non-verbal cues when they try to deceive. These are the basis of “lie detector” tests.
They include:
Prosodic speech variation
Skin conduction (due to sweating)
Breathing and heart rate changes
Particular body gesture cues
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13. Trust and deception
Facial expression on the other hand, since it is consciously managed, is a poor cue to deception.
Most deception cues therefore, are “below the neck”.
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14. Trust and deception
A former president:
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15. Trust and deception
A former president:
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16. Trust and deception
A former president:
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17. Gaze distortion
Its physically impossible with standard video displays to preserve gaze for a group of people on either side of a video connection. Unfortunately, that is the most common case in commercial settings. B
Make text bigger
Mehrabian’s findings could partially explain what’s going on here.
Bos’ Paper
Measure development of trust in group settings
NOT DYADIC
Trust is widely applicable
Groups communicated using one of four different communication channels
Text
Voice
Voice+Video
FTF
Trust was measured using a Daytrader game (variant of prisoner’s dilemma)
Findings
In FTF, high level of trust immediately attained and maintained through the game
Delayed Trust – Audio/Video channels required some amount of time before achieving FTF level of trust
Fragile Trust – Those using Audio/Video had a higher likelihood of someone defecting
No significant different in trust development patterns when adding a video channel
What are the factors that caused there to be no effect when adding a video channel? How do we address these factors? A
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18. Gaze distortion
Only A believes that the other person is looking at them!
This is because of the Mona-Lisa effect. B
Make text bigger
Mehrabian’s findings could partially explain what’s going on here.
Bos’ Paper
Measure development of trust in group settings
NOT DYADIC
Trust is widely applicable
Groups communicated using one of four different communication channels
Text
Voice
Voice+Video
FTF
Trust was measured using a Daytrader game (variant of prisoner’s dilemma)
Findings
In FTF, high level of trust immediately attained and maintained through the game
Delayed Trust – Audio/Video channels required some amount of time before achieving FTF level of trust
Fragile Trust – Those using Audio/Video had a higher likelihood of someone defecting
No significant different in trust development patterns when adding a video channel
What are the factors that caused there to be no effect when adding a video channel? How do we address these factors? A
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19. Mona Lisa Effect
In this slide, we simulate different perspective by virtually rotating the mona lisa.
For each rotation, we grab an image of only the face (to remove the context of the perspective lines.
We see that viewing at 0 and 50 degrees still looks like she’s looking directly at us.
There is only a transformation in the horizontal direction.
Sometimes known as horizontal parallax 10 20 35 50
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20. Solutions
Props (mobile presences) address some of these issues. They even support exploration.
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21. MultiView Display 1 2 3
Line up rays with eyes.
Light is retroreflected toward the source in the horizontal direction.
Each user has their own projector, sees their own image.
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22. MultiView Directional Display
Each view is provided by a projector
The projected image is reflected directly back in the direction of the projector
The image can be seen at varying heights only behind the projector
Each user gets video from a unique camera at the other end.
The MultiView display is a multiple element screen. Each view is provided by it’s own projector. The image from the projector is reflected directly back in the direction of the source in a way that the image can be seen at varying height behind the projector.
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23. Cameras
Projectors
MultiView
Display
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24. 1 2 3
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25. 1 2 3
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26. 1 2 3
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27. MultiView Display
The Multiview design fully preserves gaze cues between all pairs of participants, on both sides of the connection.
It also reproduces everything that’s visible above the table at the other end (same deception cues as a face-to-face meeting).
Goal is to see if we can reproduce persuasion and trust cues.
The MultiView display is a multiple element screen. Each view is provided by it’s own projector. The image from the projector is reflected directly back in the direction of the source in a way that the image can be seen at varying height behind the projector.
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28. CSCW Evaluation Evaluation of CSCW systems is difficult because of:
Logistics of data collection (separated in time and space, and huge).
Number and complexity of variables.
Validating re-engineered group work.
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29. Logistics of data collection
Suggestions?
Get partners for other locations
Self-reports
Instrument! – record everything in the system
Video – get if at all possible
Get context information
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30. Number and Complexity of Variables
Suggestions?
Start with some hypotheses – but keep eyes open
Iterate on experiment design
Keep user tasks simple – caveat about considering entire cooperative activity
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31. Validating re-engineered group work
Suggestions?
Long-term evaluations
Co-evolutionary design
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32. Livenotes: Collaborative Note-taking
Pen and keyboard input
Unique user color
Import background slides
Small peer group
Group awareness
Pages that users are on
The UI that was developed in Java. Performance issues with Clios as we added more features.
Notebook metaphor
Shared whiteboard
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33. Client-Server Topology
Group 1:
Server
802.11b networking
Large class broken down into many small groups (3-7 students)
One Tablet per group is set to server mode
Other members’ Tablets connect wirelessly to group’s server
Clients …
Group n:
The UI that was developed in Java. Performance issues with Clios as we added more features.
Server
Clients
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34. Experiment Spring 2003 undergraduate HCI class
21 volunteers, randomly partitioned into
Cooperative note-takers
Individual note-takers (control group)
4 weeks (7 lectures)
Preloaded skeletal PowerPoint slides
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35. Previous Observation From previous deployments, we learned that
Undergraduates were not used to discussing lecture material with one another
Graduate students engaged in group discussions spontaneously
Required students to do these face to face discussions to stimulate on-tablet discussions
For this experiment (with undergraduates), we held short, live group discussions in the classroom
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36. Cooperative Note-Taking: Richer Notes
Average cooperative note-taking group took more than twice as much notes as individual note-taker.
Average cooperative note-taking group has more commentary, question and answer, and reinforcement marks (46.4%) than individual note-taker (7.6%), above simply note-taking
24.6% of marks attributed to group interaction
Make the connection to hypothesis #1.
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37. Cooperative Note-Taking: Richer Notes
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38. Augmented Note-Taking: Observed Behaviors
Elaborated on bullets
Appended bullets to list
Concurred and disagreed with bullet
Noted gist of HCI principles
Noted advantage and disadvantage of HCI technique
Answered questions in bullets
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39. Elaborating on Bullets
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40. Appending Bullets to List
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41. Answered Question in Bullet
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