[RandomWorker]

Also how did you prevent people finding both postings? When searching for jobs if identical they will appear in the same list. Also the smart ones applying will apply on the one without because of all the various biases that the poster has and they will play some reverse psychology.

[clairity]

yes, this is a major flaw in their analysis. there's no way to draw a reliable conclusion because the experiment is uncontrolled in this way, among other factors (like the subjective evaluation of candidate quality which was also uncontrolled for).