[violetthrift]

If there was a placebo effect, I would expect there to be a significant difference in the participants' self-reported sleep quality, but there was not:

> Sleep diary data revealed no differences in the number of hours slept while wearing the eye mask (7.15 ± 16.66) or the control mask (7.18 ± 16.82; t(23) = −0.11, p = .914, N = 24). Likewise, there was no significant difference in self-rating of sleep quality (eye mask: 3.13 ± 0.19 vs control: 2.84 ± 0.16; Z = −1.53, p = .131, N = 31).

[anonymouskimmer]

Those sleep quality measurements barely overlap at 1 SD. I don't care if anyone says it's not statistically significant; the trend is enough that I would not be convinced without a lot of additional data which pushes the mean values much closer together.