To continue with our story, these participants are randomly assigned to either
the control group, where they take the placebo pill, or the experimental group,
where they take the active pill. They take the pill at the same time of day, on
the same day, and the same place. And then, they all go to bed in a sleep lab at
the same time. While sleeping, researchers observe the particpant's sleep
patterns and rate their quality of sleep. Do you think these researchers should
or should not know which treatment participants received? Why or why not? Yes,
because their ratings will depend on which treatment the people received. No, to
help maintain participant confidentiality. Yes, because the researchers ratings
will be more accurate. Or no, because if they know, their judgements may be
biased. What do you think?