you’d expect the difference in placebo-caffeine scores to drop
I am not sure about this. I could also imagine that the difference remains similar, but instead the baseline for concentration etc. shifts downwards such that caffeine-days are only as good as the old baseline and placebo-days are worse than the old baseline.
I am not sure about this. I could also imagine that the difference remains similar, but instead the baseline for concentration etc. shifts downwards such that caffeine-days are only as good as the old baseline and placebo-days are worse than the old baseline.
That’s a good point, I’ll keep it in mind.