Do

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Dos and Donts of using Videoconferencing for
Remote Teaching A Human Factors Approach

• Milton Chen, PhD
• Human Computer Interaction Lab
• Stanford University
• Presented at the 21st NORDUnet Network Conference
  8/27/2003

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Executive Summary

• Dont use video if the task doesnt need it
• Dont use non-fluent video
• Dont make call setup difficult
• Dont use voice activated switching
• Dont sacrifice audio
• Do show self view
• Do show audience

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Distance education at Stanford
a 2003 operator console
a 1969 classroom
a 2003 lecture viewer

• 6000 students, 20 M in tuition each year
• Can hear but not see the remote students

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Consequence of not seeing the students

• Little interaction with remote students
• Local students asked 3 questions per session
• Remote students asked 1 question in 6 month
• based on classroom observation of 4 CS
  classes

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F2F interaction is crucial for discussions
120 students, 15 TAs, and 41 faculty
Report to the School of Engineering Deans
Office 01
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Distance learning
The vision any where, any time
The reality any where, any time except live

• The consequence

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The Stanford Video Auditorium
15 x 5 video wall
desktop interface
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The Stanford Video Auditorium
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Accomplishments

• Intel President Paul Otellini demonstrated vsee
  during his keynote at IDF
• Candidate system for International Space Station
• With Bob Bradford, MSFC
• Featured Internet2 project to break video wall
  record
• Attempt to see all 200 members of Internet2
  simultaneously

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Videoconferencing Solutions
Max video links Max video resolution Bandwidth at 352x288 15fps
Microsoft NetMeeting, Yahoo Super Webcam 1 352x288 200 Kbps
Polycom, Tandberg, 4 352x288 200 Kbps
vsee 16 720x480 100 Kbps
At 30 fps on a 3 GHz Pentium 4
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Instructors view
Students view
Independent Students





















Stanford
Iceland
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The great expectation
expectation
19271st demo by ATT
1964 PicturePhone
1991/92Mbone VIC CUseeMe
1996 NetMeeting
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1st Revolution Possible
2nd Revolution Ubiquitous
first mobile phone, 1924
first handheld phone, 1973
first videophone, 1927
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We express ourselves into existence. -
Iris Murdoch
Tyranny of real classrooms vsee A history of
failures Harmful effect of video
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Harmful effect of video

• Time and resource sink
• Make user look bad
• Gaze less potent gt are you ignoring me?
• Gesture less potent gt am I not interesting?
• Slow response gt user is slow?
• Lack of lip sync gt user is not believable?
• Lack of eye contact gt user is not motivated?
  Reeves and Nass 96

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Eye contact stirs us to action
Sharbat Gula, photographed by McCurry 83
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Eye contact fires up our brain
Kampe et al. 01 Nature
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Methodology
Large display with camera at the center
Observers watch videos of looker
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Eye contact?
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Sensitivity is asymmetric
16 observers judged recorded videos of 1 looker
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An anatomical explanation
looking at you
looking sideways
looking up
Illustrations from The Artists Guide to Facial
Expression Faigin 90
eye closing
looking down
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We shape our tools, and there after our tools
shape us - Marshal McLuhan
Tyranny of real classrooms vsee A history of
failures Harmful effect of video Eye contact
finding Lip sync finding
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Why read lips

• Improves comprehension
• Background noise Sumby and Pollack 54
• Hearing loss Binnie, Montgomery, Jackson 86

Yarbus 67
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Audio ahead of the video

• Videoconferencing
• 1 msec to encode 30-msec audio with TrueSpeech
• Up to 250 msec to encode a 720x480 frame with
  high-quality MPEG-4
• Detectable skew
• 130 msec Dixon and Spitz 80
• 80 msec Steinmetz 96

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Conventional lip synchronization
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Attribute delay and skew to remote person

• gt person is slow?
• gt person is not believable?
• Reeves and Nass 96

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A new lip sync method
a
v
a
v
sync
decode
network
encode
synchronized and low perceived latency
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Methodology

• Recorded 3 speakers
• 44.1KHz x 16 bps uncompressed audio
• 320x240x30fps uncompressed video
• Sentences consist of easy to lipread words

Speaker 1 female native speaker
Speaker 2 male native speaker
Speaker 3 male non-native speaker
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Perception of variable AV skew
16 subjects judged recorded videos of 1 speaker
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The heart is stirred more slowly by the ear
than by the eye. Horace
Tyranny of real classrooms vsee A history of
failures Harmful effect of video Eye contact
finding Lip sync finding Dos and Don'ts
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1. Dont use video if you dont need it
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Benefit of video medium

• Facilitate communication process
• Stimulate interactivity when group is medium size
• Support tasks that require complex collaboration
• Negative feedback
• Negotiation
• Build relationship
• Establish identity
• Build trust
• Form friendship

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2. Dont use non-fluent video
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A language fluency model for videoconferencing

• Are you fluent in videoconferencing ?
• Factors that make gaining fluency difficult
• Disruption
• Audio quality lt 8KHz x 8 bits per sample
• Video quality lt 320 x 240 x 10 fps
• Loss of control
• Voice-activated switching
• Room-to-room
• Expressiveness
• No lip sync
• No eye contact

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3. Dont make call setup difficult
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Videoconferencing today?
Ericssons mobile phone, 1901
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4. Dont use voice activated switching
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3 sins

• Activate peripheral vision
• Out of sight out of mind
• Artificial social hierarchy

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5. Dont sacrifice audio
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Less tolerant of audio artifacts

• Push button to talk
• Half-duplex
• Latency
• Network loss

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6. Do show self view
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Mental model discrepancy

• We think face-to-face
• We see through a tube

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7. Do show audience
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Convey vs. feedback

• Where do you actually look?
• The typically class layout

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Dos and Donts

• Dont use video if the task doesnt need it
• Dont use non-fluent video
• Dont make call setup difficult
• Dont use voice activated switching
• Dont sacrifice audio
• Do show self view
• Do show audience

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What is a videophone
A plane that does not fly is not a plane
First flight, Wrights 1903
A videophone that limits communication is not a
videophone
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Summary

• Tyranny of real classrooms
• Case study not seeing gt no participation
• VSee
• A history of failures
• Poor video can be worse than no video
• Findings on eye contact and lip sync
• Dos and Donts

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• Acknowledgement
• Prof. Ebba Hvannberg
• Prof. Pat Hanrahan and Terry Winograd
• Prof. Cliff Nass, Tom Moran, Anoop Gupta
• I would love to hear from you!
• http//vsee.stanford.edu
• Collaborate on the Internet2 demo?