Phase changes are the way something alters it behaviour as an environmental variable hits a certain threshold.  In the physical world Water changes from solid to liquid as temperature and pressure hit a certain level.

In social organization, group size and group super-ordinate goal determine effective size.  A good example of this is the Dunbar number.

The thinking is that the roles and function of a group changes relative to its size.  This could be construed as an attempt to create a constructal theory for people, a Nick Gogerty original idea.

Anthropologist crudely organize groups into:

• individual
• band
• tribe
• nation

These groupings are crude, fluid and overlapping based on identity, geography and other factors.

Social media tools allow for a mix of activities in a non-geographically constrained space.

• Grazing
• Creating
• Glancing
• Sharing
• Venting (anger elation)  strictly Emotional vs. functional communication
• Elaborating
• Organizing
• Gating limiting/ editing
• Destruction

Understanding the limits and effective management of individuals abilities, motivations and actions within various digital environments and context might allow for the more effective design and deployment of social media for various goals. 

The objective of a social media constructal model would be to determine for each tool:

• wiki
• Blog
• Threaded conversation
• Video site
• Twitter account
• Myspace facebook home
• E-mail
• SMS

what are the limits to effective participation in the roles described above?

What are the motivations to take up or participate in one of the roles above?

How can we create media that instills or activates beliefs leading to desired constructive group or individual activities?

Social media as a unconstrained geographic space allows for a broader range of behaviour due to anonymity, lower social costs and multiple personae.  Understanding how to manage adverse participants, desires and/or encourage positive participation and motivators is an important area for study.