They did not examine the content of contaminants or chemical residues.
Well, it turns out RODALE and the Organic Center BOTH disputed this article wrote the researchers. There were holes all over the article and the study. The study looked at 13 nutrients which in the organic folks opinion, wasn't near enough and didn't include antioxidants which are huge in organic food. The study also did not release everything they found -- only the parts they felt showed similar comparisons, thus there's no difference. Ahhh... working with data...all it takes is a smart person to use the parts they want to use and they can say "here's the proof!" but they don't tell you everything in the data. It's all based on who you're working for and what message you want to get out. So here is the Organic Center's response. And here is Rodale's response. The Organic Center really goes into great detail and even did their own study of the same data and found huge differences. Very interesting read if you have the time (yes, it's long).