As a part of my Ph.D. thesis, I was working on prosthetic foot design, so I need to do many experimental investigations on amputee persons, and at the time many of my cases (patients) were in very bad temper due to different factors, so I have to spend long time to get accurate information about their medical indication about the manufactured and developed artificial foot, this is the first part, meanwhile, when I return my office to analyze the gained results (represents pure science part), I feel so free with out any disturbance with quite mind and get very efficient results. So the conclusion can be drawn is manipulating with human is very difficult in opposite when just dealing with pure sciences.
I appreciate your difficult and fruitful experience and I like to thank you for sharing it with us. On the other hand, concerning my question, sometimes to deal with people experimentally is also very difficult and this what happened with most applied human sciences researches.