Tell me more ×
Cross Validated is a question and answer site for statisticians, data analysts, data miners and data visualization experts. It's 100% free, no registration required.
up vote 0 down vote favorite

The title is my whole question.

share|improve this question
3  
By $x$ & $y$ in the ROC curve, I gather you mean the False Positive Rate & the True Positive Rate, right? – gung Dec 24 '12 at 15:31
Yes, precisely. :) – Pippo Dec 24 '12 at 16:06

1 Answer

up vote 2 down vote accepted

If you classify a fraction $k$ of your cases as positive then, because of the randomness, the same fraction $k$ of cases which should be positive will be classified positive (true positives), and the same fraction $k$ of cases which should be negative will be classified positive (false positives).

So the true positive rate and the false positive rate are the same.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.