double-blind study
A medical experiment where neither the testers nor the subjects have any idea what they're doing or what the actual risks might be. Why, for all the testers know, they themselves might also be accidentally ingesting the substance under test and be totally unaware of this fact, as well --- NOT a healthy or safe situation.
The infamous ‘Elephant Man’ drugs-trial --- all six of the test-subjects nearly died --- is a classic case of a double-blind study gone horribly wrong --- talk about the blind leading the blind!