Probabilities (General)

by dhw, Thursday, April 17, 2014, 19:59 (3655 days ago) @ romansh

ROMANSH: Here's a question
what is your immediate response?
Imagine you are in your doctor's office and she says, "well the results have come in from the tests and you may have that ailment we were discussing." You ask, "what is the false positive rate?" and she replies "five percent with no false negatives." You then ask "does that mean there is a ninety five percent chance that I have the ailment?"
What is her correct reply? If you 'know' the correct answer please hold off anwering for a bit.-************-ROMANSH: OK so no one hazarded a guess. Either no one wanted to admit not knowing or they knew. Perhaps they did not care enough to reply. Fair enough. Well the doctor's reply should be along the lines ...
Well Mr rom you can't come to that conclusion as I have not given you enough information.
So what is the piece of missing information that we need?-Having studied some of the works of "Mr rom", I'm afraid I shall have to change my doctor immediately. There is obviously not just one piece of information missing, but several. Firstly, I can't even be sure that she IS a doctor, or that she has read the report properly, or that the people who compiled the report knew what they were doing, or that the research preceding the fixing of these suspiciously round figures was properly carried out (all these folk fighting for their grants)...but I will ignore all of those and merely concentrate on one crucial factor in this problem, which is hinted at by the identity change of the patient between your two posts, from "you" to "Mr rom".
 
According to the "Mr rom" whose works I have been studying in recent weeks, our cells are not our cells. Only language forces him to say they are. And so quite clearly we need to know exactly whose cells were sent for testing, and who (or even what) is Mr rom? And if Mr rom still claims to be Mr rom, and if the doctor really is a doctor, she should bear in mind that the self is not what it seems, in which case Mr rom is not what he seems, just as the samples, tests, researchers and results may not be what they seem. The reply I would expect from the doctor (if she IS a doctor) is therefore: "I do not know."
 
I have had my fun. Now, Mr rom, you can have yours and tell us YOUR (not "the correct" ... ts ts!) answer.