On ProBoards forums (Number of boards hosted: 3,079,999) there is an Admin option to enable Karma. This is a system of saluting or dissing your fellow members. It always leads to grief, if not outright wars between members. Karma, which is more or less what you're advocating, turns into a way of exalting perceived friends and spiting perceived enemies. I've seen it over and over again and by GODS is it tedious.
I've seen that, too, on Craigs List forums.
I've wondered if it could perhaps be made gentler by making it a single-edged sword. Allow people to mark a post "helpful" but not allow negative votes. I think it's the possibility of smacking someone down more or less anonymously that feeds the mean streak in some raters.
But then I remember that the other problem with rating systems is voter fraud. People will try to game the system by opening multiple accounts so they can get multiple votes and/or vote for themselves. There are complex methods of detecting this (for example, watch for users who always log in concurrently or sequentially), but the effort required quickly exceeds any possible return.
I think we're on the right path, not trying to evaluate posters at all. If you hang around here long, you'll learn who gives good advice and who doesn't. If you haven't been here long, well, like Archimedes said to the king, "There is no royal road to Geometry." So be it. Advice to newbies freely given, but asking us to rate the advice too is maybe asking too much.
Bad advice will be corrected anyway, if they check back in a few days. (OK, maybe that's asking too much. How many times have you seen someone post a question and then to all appearances never come back to look at even the first answer?) If they do check back, the thread consensus is almost certainly more useful to them than individual ratings anyway, especially as it's focussed directly on their problem.
