> Why is it poor quality? While the scoring was done in a double-blind fashion, it's still completely subjective. Maybe the person scoring the tests had just e

> Why is it poor quality? While the scoring was done in a double-blind fashion, it's still completely subjective. Maybe the person scoring the tests had just eaten a meal before scoring the tests with the alpha-wave frequency stimulation (which has been shown to increase scores that people give in general). Maybe the grader was hungover for the tests with the bad scores. Maybe the grader was being paid $9/hour and just assigned scores at random out of apathy. Maybe the participants just happened to be in better moods on the day they did the alpha-wave frequency test. Having only 20 participants and doing a single trial of each frequency leaves the study vulnerable to small effects like the ones I just mentioned. Do you believe that all of those things, plus all of the factors I haven't even thought of combined couldn't result in just a 7.4% variance in scores? If the study had a control group we might know. Or if they had a much larger sample size we could rule out random variation. So it's not that 7.4% is a small but interesting result, it's that it's not a result.