It's a two-valued poll, you only get a binary choice, if you upvote 90% of the time after reading an article and 10% before then 'after' would still be the best choice (and that's what it would be in my case, the upvotes I do 'before' are of ask HN articles that I think ask valid questions).
That's a good point. I was just noting that even if someone voted 90%-10% the other way he or she would probably not respond to this poll truthfully, given the tendency here to look down on those who don't think before they do. I'd be surprised if "vote before reading" gets more than zero votes.
Yeah, I was mildly confused too by the fact that the articles you've upvoted are called "saved" articles in your profile.
Anyway after once having upvoted w/o reading an "advanced data structures" article which turned out to be extremely far from "advanced", I at least try to skim before upvoting.