Milton

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  • Milton

    1. 1. Do’s and Don’ts of using Videoconferencing for Remote Teaching: A Human Factors Approach Milton Chen, PhD Human Computer Interaction Lab Stanford University Presented at the 21 st NORDUnet Network Conference 8/27/2003
    2. 2. Executive Summary <ul><li>Don’t use video if the task doesn’t need it </li></ul><ul><li>Don’t use “non-fluent” video </li></ul><ul><li>Don’t make call setup difficult </li></ul><ul><li>Don’t use voice activated switching </li></ul><ul><li>Don’t sacrifice audio </li></ul><ul><li>Do show self view </li></ul><ul><li>Do show audience </li></ul>
    3. 3. Distance education at Stanford <ul><li>6000 students, $20 M in tuition each year </li></ul><ul><li>Can hear but not see the remote students </li></ul>a 1969 classroom a 2003 operator console a 2003 lecture viewer
    4. 4. Consequence of not seeing the students <ul><li>Little interaction with remote students </li></ul><ul><ul><li>Local students asked 3 questions per session </li></ul></ul><ul><ul><li>Remote students asked 1 question in 6 month </li></ul></ul><ul><li> </li></ul><ul><li> * based on classroom observation of 4 CS classes </li></ul>
    5. 5. F2F interaction is crucial for discussions * 120 students, 15 TAs, and 41 faculty <ul><ul><li>[Report to the School of Engineering Dean’s Office ’01] </li></ul></ul>
    6. 6. Distance learning <ul><li>The consequence </li></ul>The vision any where, any time The reality any where, any time except live student of the future teacher of the future
    7. 7. The Stanford Video Auditorium desktop interface 15’ x 5’ video wall
    8. 8. The Stanford Video Auditorium
    9. 9. Accomplishments <ul><li>Intel President Paul Otellini demonstrated vsee during his keynote at IDF </li></ul><ul><li>Candidate system for International Space Station </li></ul><ul><ul><li>With Bob Bradford, MSFC </li></ul></ul><ul><li>Featured Internet2 project to break video wall record </li></ul><ul><ul><li>Attempt to see all 200 members of Internet2 simultaneously </li></ul></ul>
    10. 10. Videoconferencing Solutions * At 30 fps on a 3 GHz Pentium 4 ~100 Kbps ~200 Kbps ~200 Kbps Bandwidth at 352x288 15fps 352x288 4 Polycom, Tandberg, … ~16 1 Max video links 720x480* vsee 352x288 Microsoft NetMeeting, Yahoo Super Webcam Max video resolution
    11. 11. Instructor’s view Student’s view Independent Students Stanford Iceland
    12. 12. The great expectation 1927 1 st demo by AT&T 1964 PicturePhone 1991/92 Mbone VIC CUseeMe 1996 NetMeeting expectation
    13. 13. first mobile phone, 1924 first handheld phone, 1973 1 st Revolution: Possible 2 nd Revolution: Ubiquitous first videophone, 1927
    14. 14. Tyranny of real classrooms vsee A history of failures Harmful effect of video “ We express ourselves into existence .” - Iris Murdoch
    15. 15. Harmful effect of video <ul><li>Time and resource sink </li></ul><ul><li>Make user look bad </li></ul><ul><ul><li>Gaze less potent => are you ignoring me? </li></ul></ul><ul><ul><li>Gesture less potent => am I not interesting? </li></ul></ul><ul><ul><li>Slow response => user is slow? </li></ul></ul><ul><ul><li>Lack of lip sync => user is not believable? </li></ul></ul><ul><ul><li>Lack of eye contact => user is not motivated? [Reeves and Nass ’96] </li></ul></ul>
    16. 16. Eye contact stirs us to action [Sharbat Gula, photographed by McCurry ‘83]
    17. 17. Eye contact fires up our brain [Kampe et al. ’01 Nature ]
    18. 18. Methodology Observers watch videos of looker Large display with camera at the center
    19. 19. Eye contact?
    20. 20. Sensitivity is asymmetric * 16 observers judged recorded videos of 1 looker
    21. 21. 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]
    22. 22. Tyranny of real classrooms vsee A history of failures Harmful effect of video Eye contact finding Lip sync finding “ We shape our tools, and there after our tools shape us” - Marshal McLuhan
    23. 23. Why read lips <ul><li>Improves comprehension </li></ul><ul><ul><li>Background noise [Sumby and Pollack ’54] </li></ul></ul><ul><ul><li>Hearing loss [Binnie, Montgomery, Jackson ’86] </li></ul></ul>[Yarbus ’ 67]
    24. 24. Audio ahead of the video <ul><li>Videoconferencing </li></ul><ul><ul><li>1 msec to encode 30-msec audio with TrueSpeech </li></ul></ul><ul><ul><li>Up to 250 msec to encode a 720x480 frame with high-quality MPEG-4 </li></ul></ul><ul><li>Detectable skew </li></ul><ul><ul><li>130 msec [Dixon and Spitz ’80] </li></ul></ul><ul><ul><li>80 msec [Steinmetz ’96] </li></ul></ul>
    25. 25. Conventional lip synchronization encode network decode A a v time Unsynchronized encode network decode sync a , v Audio delay line A delay skew
    26. 26. Attribute delay and skew to remote person <ul><ul><li>=> person is slow? </li></ul></ul><ul><ul><li>=> person is not believable? </li></ul></ul><ul><li> [Reeves and Nass ’96] </li></ul>encode network decode A a v time Unsynchronized encode network decode sync a , v Audio delay line A delay skew
    27. 27. A new lip sync method encode network decode sync synchronized and low perceived latency a v a v encode network decode A a v time Unsynchronized encode network decode sync a , v Audio delay line A Round trip delay
    28. 28. Methodology <ul><li>Recorded 3 speakers </li></ul><ul><ul><li>44.1KHz x 16 bps uncompressed audio </li></ul></ul><ul><ul><li>320x240x30fps uncompressed video </li></ul></ul><ul><ul><li>Sentences consist of easy to lipread words </li></ul></ul>Speaker 1 female native speaker Speaker 2 male native speaker Speaker 3 male non-native speaker
    29. 29. Perception of variable AV skew * 16 subjects judged recorded videos of 1 speaker
    30. 30. Tyranny of real classrooms vsee A history of failures Harmful effect of video Eye contact finding Lip sync finding Do’s and Don'ts “ The heart is stirred more slowly by the ear than by the eye .” – Horace
    31. 31. 1. Don’t use video if you don’t need it
    32. 32. Benefit of video medium <ul><li>Facilitate communication process </li></ul><ul><ul><li>Stimulate interactivity when group is medium size </li></ul></ul><ul><ul><li>Support tasks that require complex collaboration </li></ul></ul><ul><ul><ul><li>Negative feedback </li></ul></ul></ul><ul><ul><ul><li>Negotiation </li></ul></ul></ul><ul><li>Build relationship </li></ul><ul><ul><li>Establish identity </li></ul></ul><ul><ul><li>Build trust </li></ul></ul><ul><ul><li>Form friendship </li></ul></ul>
    33. 33. 2. Don’t use “non-fluent” video
    34. 34. A language fluency model for videoconferencing <ul><li>Are you fluent in videoconferencing ? </li></ul><ul><li>Factors that make gaining fluency difficult </li></ul><ul><ul><li>Disruption </li></ul></ul><ul><ul><ul><li>Audio quality < 8KHz x 8 bits per sample </li></ul></ul></ul><ul><ul><ul><li>Video quality < 320 x 240 x 10 fps </li></ul></ul></ul><ul><ul><li>Loss of control </li></ul></ul><ul><ul><ul><li>Voice-activated switching </li></ul></ul></ul><ul><ul><ul><li>Room-to-room </li></ul></ul></ul><ul><ul><li>Expressiveness </li></ul></ul><ul><ul><ul><li>No lip sync </li></ul></ul></ul><ul><ul><ul><li>No eye contact </li></ul></ul></ul>
    35. 35. 3. Don’t make call setup difficult
    36. 36. Videoconferencing today? Ericsson’s mobile phone, 1901
    37. 37. 4. Don’t use voice activated switching
    38. 38. 3 sins <ul><li>Activate peripheral vision </li></ul><ul><li>Out of sight out of mind </li></ul><ul><li>Artificial social hierarchy </li></ul>
    39. 39. 5. Don’t sacrifice audio
    40. 40. Less tolerant of audio artifacts <ul><li>Push button to talk </li></ul><ul><li>Half-duplex </li></ul><ul><li>Latency </li></ul><ul><li>Network loss </li></ul>
    41. 41. 6. Do show self view
    42. 42. Mental model discrepancy <ul><li>We think face-to-face </li></ul><ul><li>We see through a tube </li></ul>
    43. 43. 7. Do show audience
    44. 44. Convey vs. feedback <ul><li>Where do you actually look? </li></ul><ul><li>The typically class layout </li></ul>
    45. 45. Do’s and Don’ts <ul><li>Don’t use video if the task doesn’t need it </li></ul><ul><li>Don’t use “non-fluent” video </li></ul><ul><li>Don’t make call setup difficult </li></ul><ul><li>Don’t use voice activated switching </li></ul><ul><li>Don’t sacrifice audio </li></ul><ul><li>Do show self view </li></ul><ul><li>Do show audience </li></ul>
    46. 46. 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
    47. 47. Summary <ul><li>Tyranny of real classrooms </li></ul><ul><ul><li>Case study: not seeing => no participation </li></ul></ul><ul><li>VSee </li></ul><ul><li>A history of failures </li></ul><ul><ul><li>Poor video can be worse than no video </li></ul></ul><ul><ul><ul><li>Findings on eye contact and lip sync </li></ul></ul></ul><ul><li>Do’s and Don’ts </li></ul>
    48. 48. <ul><li>Acknowledgement </li></ul><ul><ul><li>Prof. Ebba Hvannberg </li></ul></ul><ul><ul><li>Prof. Pat Hanrahan and Terry Winograd </li></ul></ul><ul><ul><li>Prof. Cliff Nass, Tom Moran, Anoop Gupta </li></ul></ul><ul><li>I would love to hear from you! </li></ul><ul><ul><li>http://vsee.stanford.edu </li></ul></ul><ul><li>Collaborate on the Internet2 demo? </li></ul>

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