Wenger makes the following statements about identity:

• "[identity in practice] is not equivalent to a self-image" (p. 151)
• "An identity ... is a layering of events of participation and reification by which our experience and its social interpretation inform each other." (p. 151)

It appears to me that Wenger is not talking about identity in general, but is carving out a specific notion of identity, calling it identity in practice, that is a type of identity that emerges from being part of a community of practice. The individual reconciles the events from the various communities that he or she belongs to, putting the various pieces together to form one identity.

This is how I interpreted Wenger:

Each person belongs to one or more communities. Identity is the interplay between the individual and the community. Identity is dynamic, will vary according to the community, and can also be seen as a buffer or membrane between the individual and the community.

Summary

The general assumption is that "people categorize others in order to render the social world a meaningful and predictable place in which we can act efficaciously." (p. 59) We place people - including ourselves - in categories as a way to handle complexity (both Malcolm Gladwell's Blink and Gigerenzer's work on heuristics may be related to this aspect of cateogorization).

Members of a social category bear to varying degrees resemblance to a category prototype, an abstraction of properties. Depersonalization is the process by which individuals are not perceived in terms of their unique characteristics and contexts, but are perceived in terms of their match to the relevant category prototype. Polarization in groups can also be explained in terms of the category prototype - "polarization emerges where people identify with a group that has a polarized prototype" (p. 64).

[Personally I found it helpful to read Sassenberg (2002) before reading this paper] 

Summary:
Definition of online community:
“online group that interacts over time around a shared purpose, interest, or need”
Note: do not consider shared resources, reciprocity, and community norms or policy to be essential features of online communities

Community design has been an art, with few attempts to apply social science theory to community design.

I am not going to try summarizing the article, due to the density and length of the material. I am focusing on two concepts I found interesting:

• self-disclosure
• adult friendship stability 

Three specific links between self-disclosure and attraction have clear empirical support:

1. people who engage in more intimate disclosures tend to be liked better than people who disclose less
2. people disclose more to those whom they initially like
3. people like others as a result of having disclosed to them

Certain types of disclosures generate discomfort in listeners and lead to avoidance.

I had previously heard skeptical reactions to this paper from researchers, and was not surprised by the skeptical reactions here.

I tried to find out if there had been a more recent study with a different methodology and found the following Pew Internet Report:

The Strength of Internet Ties
The internet and email aid users in maintaining their social networks and provide pathways to help when people face big decisions
Jeffrey Boase, John B. Horrigan, Barry Wellman, Lee Rainie
January 25, 2006

They surveyed 2,200 adults age 18 and older, from February 17, 2004, through March 17, 2004.

I agree with the points Brian and Jesse have raised regarding the polarizing effects of the Internet, especially the difference between production and consumption of content.

Concepts:
Group polarization: "after deliberation, people are likely to move toward a more extreme point in the direction to which the group's members were originally inclined." (p. 65)

Explanations for group polarization:
1. Role of persuasive arguments
2. Social comparison - people want to be perceived favorably by other group members.

Enclave deliberation: form of deliberation that occurs within more or less insulated groups, in which like-minded people speak mostly to one another. Benefit is that it provides a voice to otherwise silent voices. (Similar to Putnam's bonding social capital)

Description
Putnam starts out with several examples of community groups across America which began fading in the last several decades of the twentieth century. He is interested in exploring what happened to civic and social life in American communities after the promise of the fifties and sixties.

Key concepts

Social capital

• connections among individuals
• social networks and the norms of reciprocity and trustworthiness that arise from them
• "civic virtue is most powerful when embedded in a dense network of reciprocal social relations" (p. 19)
• social capital can have negative manisfestations (sectarianism, ethnocentrism, corruption)

Dimensions of social capital