1. 16.499: cscw Computer-Mediated Communication Michael Bernstein 14 February 2007

2. 2 123123 CMC

3. 3 Cognotor 123123

4. 4 Meeting Central 12 3

5. 5 123123 CMC

6. 6 Computer-Mediated Communcation Studies “the social effects of different computer-supported communication technologies.” [Wikipedia]

7. 7 Computer-Mediated Communcation The Social Effects of Communication that relies on Technology

8. 8 Examples Text Chat Video Chat Audio Chat Group Chat E-mail BBS Communication in online games, MUDs

9. 9 Why is it difficult? Edward: [laughs] Michael: …huh? Edward: OK, gotta go! Michael: You are so weird. [click]

10. 10 Why is it difficult? Different communication systems have different affordances. These affordances have direct effects on what is or isn’t social acceptable. How do we understand what design decisions will carry what meaning?

11. 11 Cognotor 123123

12. 12 What was Cognotor? A tool for facilitation of plan and outline creation – a brainstorming device Support for both private and public workspaces Emulate a whiteboard through networked computers and a shared display

13. 13 How Cognotor Worked

14. 14 Design Decisions Separate screens for each user Private edit window – nobody can see items you’re trying to post to their screen until you finish Anonymous contributions, anonymous changes

15. 15 Problems Group 1: gave up, used paper individual work without communication Group 2: stopped using input and just shared video streams Users wanted to see things in the workspace that were currently invisible Users mistook each others’ spoken references: “that”

16. 16 Parcel-post Communication Model “ I want a Hamburger. ” 001101011010 1010101010111 101010100011 Stacey desires a hamburger Encoding Decoding

17. 17 Parcel-post Communication Model Information comes in discrete units, like packages Each parcel will be understood There is a queue of unseen parcels

18. 18 Interactive Model of Communcation Conversation is a highly coordinated activity… - Continuous - Requires frequent feedback …in which meaning is attained by a variety of mechanisms… - Multiple channels of information …that have context dependent functions. - Each move projects onto the next one - Midcourse corrections

19. 19 Problems identified Parcel-post model impeded the interactivity of the conversation Significant delay times Loss of context with anonymous contributions and unannounced changes Individual screens mean less visual context and mutual engagement

20. 20 Fixes Shared editing Shape and positions consistent across machines

21. 21 Meeting Central 12 3

22. 22 The Problem Distributed meetings continue to have difficulties

23. 23 User research 1,752 Sun employees responded to an internal survey Audio problems: cannot hear people, poor audio quality, extraneous noise Behavior problems: speakers do not check for understanding Technical problems: difficult to identify speaker, not everyone could view materials, no way to tell who was in the meeting

24. 24 Meeting Central: The Facilitator Hand raising, to indicate desire to speak Invited but not in attendance Speaking Indicate support or confusion (back channel) Passive feedback indicators Whisper feature

25. 25 Later work: MC 2.0 Renaming the whisper feature to “voice chat” [CHI 2005: posters]

26. 16.499: cscw Discussion msbernst@mit.edu Thanks to Scott Klemmer, Ron Yeh and Stanford HCI for slide designs