Cross Validated is a question-and-answer site dedicated to statistics and statistical computing. It is part of the completely awesome Stack Exchange network of Q/A sites which I rely on heavily when coding. The questions range from the fairly straightforward (“How can a regression be significant yet all predictors be non-significant?”) to the fairly complicated (“What’s the difference between principal components analysis and multidimensional scaling?”) to the fairly abstract (“How are we defining ‘reproducible research’?”).

There is a ton of interesting instruction being done there. I have heard others scoff at the idea of giving away your expertise for free on sites like these, but I think that Cross Validated and other sites are crucial and vibrant places for students to learn about statistical methods. And this is a chance to actually help people in a concrete way.

Also, check out their community blog, which promises to have great little tidbits, mostly focused on R.

Posted by Matt Blackwell at September 27, 2011 9:17 AM