Update: This week, Ars staffers from across the country gather together in real life for our annual meeting, Technicon. We're supposed to be talking more than typing, so we're resurfacing a few classic Ars stories just in case the front page gets lonely. This one, which originally ran on November 3, 2010, centers on our peers (the scientific ones, not the Arsians) and the two basic functions of the much-discussed "peer review."

It is often said that peer review is one of the pillars of scientific research. It is also well known that peer review doesn't actually do its job very well, and, every few years, people like me start writing articles about alternatives to peer review. This isn't one of those rants. Instead, I'm going to focus on something that is probably less well known: peer review actually has two jobs. It's used to provide minimal scrutiny for new scientific results, and to act as a gatekeeper for funding agencies.

What I would like to do here is outline some of the differences between peer review in these two jobs and the strengths and weaknesses of peer review in each case. This is not a rant against peer review, nor should it be—I have been pretty successful in both publications and grant applications over the last couple of years. But I think it's worth exploring the idea that peer review functions much better in the case of deciding the value of scientific research than it does when acting as a gatekeeper for scientific funding.