Expertise Ratings

I was going to just mention this in a comment, but I think it's significant enough to have a real post of its own. Jon mentioned this in a reply to my last post:

Judging from your analysis of credibility versus expertise, I'd say this graph was useful to you. I'm not sure I always agree with your decisions; for example, maybe Alan Sokol's substantial expertise in physics should translate into credibility when he's talking about cultural studies. But that's up to you, and no one solution is going to be best.

He's talking about something I had been discussing with him for a while, which is determining a person's expertise in different subject areas. Just to clarify, I'm no longer looking at expertise as a calculable data, either globally or in a specific field. Expertise is claimed by a poster, and is a post-specific claim; credibility is the measure of whether or not that claim is valid, and is a global metric based on the reviews of the community. I am still trying to determine a way to use real-world data like citations to determine a user's initial credibility, but I'm only looking at this as a way of bootstrapping the community calculations.

A user's expertise will translate to credibility when they claim significant expertise and the community agrees with them. As mentioned in my last post, ratings on a post where a user claims high expertise are weighted quite a bit heavier than ratings on a non-expert post when determining global credibility. Credibility is not just a measure of how expert a person is; it is also a measure of whether they know when they are an expert and when they aren't.