(August 17, 2014 at 8:30 am)Michael Wrote: Thump, with respect I have to correct that. The control you pick depends on the question you are asking. For example, I'm a biomedical researcher, so I have frequently been involved in trials on the efficacy of medicines. If we're looking at whether a new asthma drug works or not, we take a group of asthmatics (and only asthmatics for efficacy trials; there is little sense in including healthy people in a test of efficacy against a particular condition) and we compare our new treatment with either another treatment (European authorities prefer comparisons against commonly used standard treatments) or with placebo (US authorities prefer placebo-controlled trials).
So a control is always specific to the question asked. In the study reported the control is a group who think about a person. The experiment then reports on the difference between test (prayer) and control (thinking about a person). We don't want to introduce different groups of people as that will confuse the results (just as we don't want to test an asthma drug in asthmatics vs a placebo in healthy people). We must then, of course, be very careful only to draw conclusion as far as the test allows. This study simply demonstrated a difference between general thought about a person and prayer. So long as we limit the conclusions to the remit if the experiment I think it's a useful experiment. Most experiments have tightly focussed aims like this. They may not seem to add much, but knowledge is often built from lots of little studies.
If you're testing for the efficacy of prayer, the control group should be a group that doesn't pray. That is the only way to isolate that variable.
