Want to explain to your students when using Wikipedia is appropriate, and when it's not, and why? Try Clay Shirky's analogy:
There’s a spectrum of authority from “Good enough to settle a bar bet” to “Evidence to include in a dissertation defense,” and most uses of algorithmic authority right now cluster around the inebriated end of that spectrum, but the important thing is that it is a spectrum, that algorithmic authority is on it, and that current forces seem set to push it further up the spectrum to an increasing number and variety of groups that regard these kinds of sources as authoritative.
It's a good reminder for us as teachers, too, with regard to understanding that authority sources like Wikipedia are here to stay, and that we have to learn how to teach with them, not against them.
For an explanation of what Shirky means by "algorithmic authority," see the blog post itself. It's a good read.
I came to it through another good read, a post by blogger Clay Burell, who's been on self-imposed hiatus; I've missed him for his clear-sighted discussions of what it means to be a teacher of the Humanities in the Digital Age. He was blogging briefly for the Education page of Change.org, but left that gig and is now back at his own original blog, Beyond School.
His returning post has a brief discussion of his struggles with his new students, who trust Google far too much to buy his arguments about "algorithmic authority." Also worth a read.