Did the experts just measure the absolute hyperactivity after treatment, or the difference in hyperactivity before and after treatment? I think measuring the difference would be the better choice to compare to parent’s judgement. (And does it matter, in practice, whether it is the same expert who measures the child before treatment as after treatment?)
They measured absolute hyperactivity over each time interval. When the study was finished, it was unblinded, so only then did they know which children were treated with the test substance during which intervals. They then subtracted the scores while on placebo from the scores while on substance. In short: They measured the difference.
It does matter who judges; standard practice is to find the correlation of all experts on a sample, and verify it’s high, before the study begins.
Did the experts just measure the absolute hyperactivity after treatment, or the difference in hyperactivity before and after treatment? I think measuring the difference would be the better choice to compare to parent’s judgement. (And does it matter, in practice, whether it is the same expert who measures the child before treatment as after treatment?)
They measured absolute hyperactivity over each time interval. When the study was finished, it was unblinded, so only then did they know which children were treated with the test substance during which intervals. They then subtracted the scores while on placebo from the scores while on substance. In short: They measured the difference.
It does matter who judges; standard practice is to find the correlation of all experts on a sample, and verify it’s high, before the study begins.