Presentation to BayChi on July 11th 2006. We are relying increasingly on internet-mediated social software tools for our day-to-day interaction with other people. To design this type of software, we must better understand the psychology and social dynamics of individuals in groups. Awareness of what makes us human is now often as important to the success of the software as is understanding software architecture and code. One particular sociological factor, the Dunbar Number, is useful in understanding why groups don't scale at different group sizes. A deeper awareness of why groups have different behaviors, the nature of unstructured trust, and which current tools appear to work best at different scales, can give guidance to both the online facilitator and the social software designer.

1. July 11, 2006
The Dunbar Number,
Unstructured Trust &
Why Groups Don’t Scale
Christopher Allen

2. The Dunbar Number,
Unstructured Trust &
Why Groups Don’t Scale
Christopher Allen

3. The Dunbar Number, Unstructured Trust &
Why Groups Don’t Scale
Dr. Robin Dunbar

4. The
Dunbar
Number
Groups Size &
Neocortex Ratio

5. The Dunbar Number, Unstructured Trust &
Why Groups Don’t Scale
Dr. Robin Dunbar
Gladwell, Watts, Buchanan, et al.

6. The
Dunbar
Number
Survival Groups

7. The
Dunbar
Number
Survival Groups

8. The
Dunbar
Number
Survival Groups

9. The
Dunbar
Number
Survival Groups

10. The Dunbar Number, Unstructured Trust &
Why Groups Don’t Scale
Dr. Robin Dunbar
Gladwell, Watts, Buchanan, et al.
Unstructured Trust

11. Unstructured
Trust
No trust

12. Unstructured
Trust
Familiar Stranger

13. Unstructured
Trust
Conversations for
Discovery

14. Unstructured
Trust
Casual Friends

15. Unstructured
Trust
The Band

16. Unstructured
Trust
The Crowd

17. Unstructured
Trust
The Mob

18. The Dunbar Number, Unstructured Trust &
Why Groups Don’t Scale
Dr. Robin Dunbar
Gladwell, Watts, Buchanan, et al.
Unstructured Trust
So what are the limits to group size?

19. Limits to
Group Size
Ultima Online
Sizes of Guilds

20. Limits to
Group Size
Ultima Online
Histogram of Sizes of Guilds

21. Limits to
Group Size
World of Warcraft
Subgraph Map of a Guild

22. Limits to
Group Size
World of Warcraft
Max Subgraph Size of all Guilds

23. Limits to
Group Size
World of Warcraft
Subgraph Ratio of all Guilds

24. Limits to
Group Size
Group Satisfaction

25. The Dunbar Number, Unstructured Trust &
Why Groups Don’t Scale
Dr. Robin Dunbar
Gladwell, Watts, Buchanan, et al.
Unstructured Trust
So what are the limits to group size?
Group size problems

26. Concept: Group Size Problems
Too Few People
Insufficient critical mass
Unable to sustain conversation
Feels like you are alone
Lack of commitment or leadership
Groupthink & Echo Chamber

27. Concept: Group Size Problems
Too Few People
Insufficient critical mass
Unable to sustain conversation
Feels like you are alone
Lack of commitment or leadership
Groupthink & Echo Chamber
Too Many People
Too noisy, not enough signal
Lack of trust, unequal trust
Cliques & bad gossip
Inappropriate politics
Other social contract failures
Flames
Trolls
Tragedy of the commons

28. The Dunbar Number, Unstructured Trust &
Why Groups Don’t Scale
Dr. Robin Dunbar
Gladwell, Watts, Buchanan, et al.
So what are the limits to group size?
Unstructured Trust
Group size problems
Appropriate social software for
different group sizes
Cycle of Flames

29. Concepts: Cycle of Flames
Cycle of Flames
Text is missing emotional cues
We over-interpret emotions
We reply at similar intensity
(Emotional Contagion)
We empathize less when emotions
are intense
Thus “Cycle of Flames”
Irony ➫ Sarcasm ➫ Insult ➫ Flame!

30. Concepts: Cycle of Flames
Cooling Flames
Avoid emotional words
should, didn’t, forgot
Avoid irony and sarcasm
When necessary, use smilies to
avoid confusion ;-)
Don’t escalate
Educate

31. The Dunbar Number, Unstructured Trust &
Why Groups Don’t Scale
Dr. Robin Dunbar
Gladwell, Watts, Buchanan, et al.
So what are the limits to group size?
Unstructured Trust
Group size problems
Appropriate social software for
different group sizes

32. Concept: Appropriate Size
Small Groups (2-12 active, best for 4-9 active)
Chat Room
Teleconference w/Backchannel
Cooperative Editor
Discussion List - Flat
Blogs - Shared only to Private
Blogs - Group Authored

33. Concept: Appropriate Size
Small Groups (2-12 active, best for 4-9 active)
Chat Room
Teleconference w/Backchannel
Cooperative Editor
Discussion List - Flat
Blogs - Shared only to Private
Blogs - Group Authored
Medium Groups (13-150 active, best for 25-80 active)
Instant Message
Avatar Chat
Discussion List - Threaded
Wiki - Single Workspace

34. Concept: Appropriate Size
Small Groups (2-12 active, best for 4-9 active)
Chat Room
Teleconference w/Backchannel
Cooperative Editor
Discussion List - Flat
Blogs - Shared only to Private
Blogs - Group Authored
Medium Groups (13-150 active, best for 25-80 active)
Instant Message
Avatar Chat
Discussion List - Threaded
Wiki - Single Workspace
Large Groups (150+ active)
Discussion List - Reputation Filterered (i.e. SlashDot)
Wiki - Multiple Workspaces
Blog - Public
Social Network

35. Blog at
http://www.LifeWithAlacrity.com
ChristopherA@LifeWithAlacrity.com