Caitlyn Pickens (a graduate student at Michigan State who is interning with us this summer) has just posted an article about the validity of different kinds of assessment. Caitlyn's goal is to build some tools we can use to gauge the impact Software Carpentry is having—like almost everything involving human beings, it turns out to be more complicated than it first appears, and her post helps lay out the background knowledge needed to understand why.

This post originally appeared in the Software Carpentry blog.