The Beneficial and Harmful Effect of Videoconferencing Milton Chen, PhD Human Computer Interaction Lab Stanford University Presented at the 21 st NORDUnet Network Conference 8/25/2003

The Stanford Video Auditorium

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

Videoconferencing Solutions Max video links Max video resolution Bandwidth at 352x288 15fps Microsoft NetMeeting, Yahoo Super Webcam 1352x288~200 Kbps Polycom, Tandberg, …4352x288~200 Kbps vsee~16720x480*~100 Kbps * At 30 fps on a 3 GHz Pentium 4

first mobile phone, 1924first handheld phone, st Revolution: Possible 2 nd Revolution: Ubiquitous first videophone, 1927

Tyranny of real classrooms vsee A new hat “We express ourselves into existence.” - Iris Murdoch

Eye contact stirs us to action [Sharbat Gula, photographed by McCurry ‘83]

Eye contact fires up our brain [Kampe et al.’01 Nature]

Eye contact?

Sensitivity is asymmetric * 16 observers judged recorded videos of 1 looker

An anatomical explanation looking at youlooking sideways looking up looking down eye closing Illustrations from The Artist’s Guide to Facial Expression [Faigin ’90]

Tyranny of real classrooms vsee A new hat 3:29 am “We shape our tools, and there after our tools shape us” - Marshal McLuhan

Why read lips Improves comprehension –Background noise [Sumby and Pollack ’54] –Hearing loss [Binnie, Montgomery, Jackson ’86] [Yarbus ’67]

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]

Conventional lip synchronization encode network decode A av time Unsynchronized encode network decode sync a, v Audio delay line A delay skew

Attribute delay and skew to remote person => person is slow? => person is not believable? [Reeves and Nass ’96] encode network decode A av time Unsynchronized encode network decode sync a, v Audio delay line A delay skew

Perception of variable AV skew * 16 subjects judged recorded videos of 1 speaker

Tyranny of real classrooms vsee A new hat 3:29 am To see or not to see “The heart is stirred more slowly by the ear than by the eye.” – Horace

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

Harmful effect of video Time and resource sink Make user look bad –Gaze less potent => are you ignoring me? –Gesture less potent => am I not interesting? –Slow response => user is slow? –Lack of lip sync => user is not believable? –Lack of eye contact => user is not motivated? [Reeves and Nass ’96]

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

Summary VSee Findings on eye contact and lip sync Poor video can be worse than no video

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