It would be a tricky experiment if the subjects were aware of the experiment. That alone taints the results. I mean these kinds of studies aren’t easy ones to do perfectly. It’s surprising how very simplistic many studies are done. A few playing cards. Blink a few times. Then again, school grades are based on a test taking place in a short time frame where your underpants might be on backwards that day and there’s a high pollen count in the air which causes sinus pressure and you’re unable to think straight, and yet your academic future depends on it…
..but I’m critical of statistical methodologies in general, especially when it comes to the ‘data collection’ stage tongue emoticon