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.