...er, I mean, "conclusions" (Ahem!) of course!
Google hits may be useful if you need to get a general sense of something, but they are seldom representative of global truth as opposed to “on-line” truth, and that, questionably so, since any neophyte with a twisted agenda can manipulate such statistical systems at will.
Remember the “miserable failure” Google-Bomb of a few years back? Case in point, no?
http://searchengineland.com/google-kills-bushs-miserable-fai...Therefore, consonant to Robert’s observation, and in spite of Google’s hit-count to the contrary, I believe that even if the more common usage is and has been, even historically, “superior”, the relatively new and almost equally widespread use of “supervisor” is more correct, in the modern context of the workplace.
peer agreement (net): +3