The Beneficial and Harmful Effect ofVideoconferencing

Milton Chen, PhD

Human Computer Interaction Lab

Stanford University

Presented at the 21st NORDUnet Network Conference 8/25/2003

The Stanford Video Auditorium

AccomplishmentsIntel 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

1 352x288 ~200 Kbps

Polycom, Tandberg, … 4 352x288 ~200 Kbps

vsee ~16 720x480* ~100 Kbps

* At 30 fps on a 3 GHz Pentium 4

first mobile phone, 1924 first handheld phone, 1973

1st Revolution: Possible 2nd Revolution: Ubiquitous

first videophone, 1927

Tyranny of real classroomsvsee

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 you looking sideways

looking up

looking down eye closing

Illustrations from The Artist’s Guide to Facial Expression[Faigin ’90]

Tyranny of real classroomsvsee

A new hat3:29 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 skew130 msec [Dixon and Spitz ’80]

80 msec [Steinmetz ’96]

Conventional lip synchronization

encodenetworkdecode

A

a v

time

Unsynchronized

encodenetworkdecodesync

a, v

Audio delay lineA

delayskew

Attribute delay and skew to remote person

=> person is slow?

=> person is not believable?

[Reeves and Nass ’96]

encodenetworkdecode

A

a v

time

Unsynchronized

encodenetworkdecodesync

a, v

Audio delay lineA

delayskew

Perception of variable AV skew

* 16 subjects judged recorded videos of 1 speaker

0

25

50

75

100

200,unsync 200,slow 200, fast sync

initial skew (msec) , stretch period

lip s

ynch

roni

zatio

n (%

)

Tyranny of real classroomsvsee

A new hat3:29 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!– http://vsee.stanford.edu

Collaborate on the Internet2 demo?