One-Factor-at-a-Time Versus Designed Experiments (site broke link so I removed it -when will people learn how to manage web content?) by Veronica Czitrom:
I still remember, as a child, asking what my father was going to be teaching the company he was going to consult with for a few days. He said he was going to teach them about using designed factorial experiments. I said, but you explained that to me and I am just a kid, how can you be teaching adults that? Didn’t they learn it in school? The article is a good introduction to the idea of why one factor at a time experiments are an ineffective way to learn.