Thursday, October 11, 2007

Homophily and Association

Responding to Artichoke:
I’ve been trying to find posts of critical analysis on the ULearn07 conference many of our teachers attended in Auckland during the school holidays. I wanted to read any critique of the new learning on offer. So it was disconcerting to read through the 427 Ulearn07 Hitchhkr links and find so little analysis and so much flocking sentiment. If I was reliant upon Hitchhikr alone for feedback on the conference I’d be tempted to conclude that ULearn07 attracted educators of such similar minds that they shared the same emotional response to all the experiences on offer - or perhaps I must conclude that blogging about an educational conference induces a Josie Fraser described homophily in educators.

What we are seeing in these communities is classic 'group' behaviour. Groups are characterized by emotional attachment to an idea or cause. Hence the 'me too' posts, as posts consisting of statements of loyalty to the group will be most valued by the group.

Group behaviour common accompanies homophily because groups are created - and defined by - similarity and identity. What's important in a group is that everybody be in some way relevantly the same. Thus it becomes important to obtain statements of conformity (in the case of hitchhkr tags) and to define boundaries.

(It is interesting to compare hitchhkr, which, because it used Technorati, demanded explicit affiliation to a group, with the conference feeds created by Edu_RSS, which, because it harvested RSS feeds directly, required no affiliation - in Edu_RSS you tend to get more criticisms and "outsiders'" perspectives).

What should be kept in mind is that homophily is only one of several means of creating associations between entities (and hence, clusters of those entities, aka 'communities').

Homophily is, essentially, simply Hebbian associationism. When neurons fire at the same time - that is, when they are stimulated by all and only the same sort of thing - they tend to become connected.

But there are other principles of association. I would like to list four (usually I list three, but I think that the fourth should become part of this picture). I'll give brief examples of each:

1. Hebbian associationism. People are connected by common interests. Affinity groups, religions, communities of practice - these are all examples of similarity-based association.

2. Accidental, or proximity-based, associationism. People who are proximate (have fewer hops between them) are connected. You may have nothing to do with your neighbour, but you're connected. The mind associates cause and effect because one follows the other (Hume). Retinal cells that are beside each other become associated through common connections.

3. Back-propagation. Existing structures of association are modified through feedback. Complain about the 'me too' posts, for example, and they decline in number. Adversity creates connections.

4. Boltzmann Associationism. Connections are created which reflect the most naturally stable configuration. The way ripples in a pond smooth out. This is how opposites can attract - they are most comfortable with each other. Or, people making alliances of convenience.

Two of these forms are qualitative. They are based on direct experience. They are not critical or evaluative. They tend to lead to groups.

The other two - Back Propagation and Boltzmann associationism - are reflective. They are created through a process of interaction, and not simply through experience. They are critical or evaluative. They tend to lead to networks.

It has been said, by way of criticism of my other work on this subject, that we need the elements of both groups and networks. That may be true. But the problem is, they cancel each other out.

Groups are based on conformity, networks are created out of diversity. Groups are based on compliance, networks are based on autonomy. Groups are closed, networks are open. Groups communicate inwardly, networks communicate outwardly.

Most social networks to date have focused on groups (indeed, they are explicitly about creating groups) and hence, on Hebbian and Accidental association. It's easy to find similarities. But the similarities are so broad (as Fraser says, sex springs to mind) the groups thus defined are formless, and when you define the similarities more narrowly, the members of the group have nothing to say to each other (other than to chant the slogans back and forth at each other).

Finding reflective connections is more difficult. We do not have automated back-propagation and Boltzmann mechanisms on the internet - it's possible that we won't be able to. Right now, the only mechanisms we have are messy things like conferences and chat rooms and discussion lists and blogs. And the connections have to be made, not by machine, but by autonomous reflective individuals.