I’d like to address an interesting topic of online expert networks. For the purpose of this post, the term ‘expert’ is very loosely interpreted to be anyone with significant knowledge of a topic. Such online networks may be blog communities (such as Expert Voices), online forums, IRC groups, mailing lists, and tracing back to the early internet, bulletin board systems (bbs). The formation and stabilization of such networks can be modeled as Professor Easley discussed in class, where each network begins at an unstable equilibrium, with the slight perturbation of ‘more users’ tips the network toward a successful, established and stable equilibrium while the perturbation of ‘less users’ tips the network toward dissolution (and certainly there is a threshold in the definition of ‘more/less’ users).

Online “expert” networks are an amazing resource. There are well established, stable expert networks for most topics one might desire to learn about, and especially discussion related to consumer products (pre and post purchase discussions). For example, if I’m trying to decide what laptop, monitor or external hard drive to buy, I can go to the tomshardware forums and find entire sections devoted to each topic with hundreds of ‘threads’ or topic discussions in each section. The same is true if I’m looking for some great new headphones. I could go to the store try to ask store employee or read the specifications, and I would probably just be horribly confused. I could try to read individual reviews posted by news websites, but I might need to read 30 of them to determine what I’m really looking for. I could also consult an expert network, such as head-fi.org, and find hundreds or thousands of people who discuss the merits of different headphones daily. They also respond to people like me who can post specific requirements and needs. I might even become so involved by making and reading posts on the site that I become somewhat of an ‘expert’ on the topic as well, in which case I can begin contributing to the network as well, thus established forums are self sustaining.

An interesting feature of online forums in particular is that the topics can be renamed and subdivided at will by the administrators of the forum. As such, emerging segregation within the forum can be made explicit by subdividing a topic. For example, computer users who are in a ‘CPU’ discussion may argue that Intel or AMD has the best processor. Initially, the forum might just have a ‘Processors/CPU’ section that includes discussion of Intel and AMD processors. Over time, forum users inevitably join one camp (at least to some extent) and segregate in to ‘AMD’ users and ‘Intel’ users. This leads to the logical creation of an ‘Intel’ subsection and an ‘AMD’ subsection. This is basically an official acknowledgement of cluster formation, although in this case we see a type of ‘hybrid’ cluster, where a user’s ‘affinity’ to a cluster need not be 1 or 0, but some value in between. I may have an affinity of 0.7 to Intel and 0.3 to AMD. This requires the density of the two clusters be defined as the sum of the affinity of each user, and each user may contribute to the density of multiple clusters. In this case, will a user prefer the higher density cluster, the cluster with an affinity closer to his own, or the one to which he has a higher affinity?

This post was prompted by an article written in 1987 about an online expert network of scientists that was used by the courts and government in general for technical advice. Read it here: http://cgi.gjhost.com/~cgi/mt/netweaverarchive/000113.html