Did you consider withdrawal effects at all? A day without caffeine having used it the previous few days is going to be very different from one where you haven’t used caffeine in months.
That’s a good point. I have, but shelved them for sometime later™. If it were true that withdrawal effects are important, you’d expect the difference in placebo-caffeine scores to drop as the experiment progresses, but I haven’t checked yet.
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.
Did you consider withdrawal effects at all? A day without caffeine having used it the previous few days is going to be very different from one where you haven’t used caffeine in months.
That’s a good point. I have, but shelved them for sometime later™. If it were true that withdrawal effects are important, you’d expect the difference in placebo-caffeine scores to drop as the experiment progresses, but I haven’t checked yet.
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.