[iQuercus]

A valuable result would be: what benefits does meditation impart over other similar activities? For example something like 30 minutes of walking every day.

A result over a non-treatment group in this case is scientifically noble, but practically useless. All it tells us is that doing something has an effect over doing nothing.

Can I get the same effects from 15 minutes of walking a day? 30 minutes? We don't know, because that wasn't compared. It should have been.