You can't, and it's a real problem for some people. Other people realize that, like testing the efficacy of parachutes by throwing two people off an airplane, o

You can't, and it's a real problem for some people. Other people realize that, like testing the efficacy of parachutes by throwing two people off an airplane, one without a parachute; other people realize the double blind standard can't be applied but that the results aren't woo mystical astrology unfounded conclusions despite that.