4 ms·
Wow, that definition is counter-intuitive. Ive expected the false-positive-rate to be the number of false positives divided by the number of all positives. Isn'
by dorgo 7y ago
Wow, that definition is counter-intuitive. Ive expected the false-positive-rate to be the number of false positives divided by the number of all positives. Isn't it how "rates" are usually defined? No wonder everybody is confused.
- deleted 7y ago[deleted]
- deleted 7y ago[deleted]
- IanCal 7y agoI think it's a perspective thing. You are looking at the rate of false results, so given a particular type of input what rate do you get it right? For negative ground truth your possible outputs are "false (positive)" and "true (negative)". I agree it can be confusing, but I think people would also make the opposite mistake if it were defined differently.
- thomasahle 7y agoYou're thinking of FDR: False discovery rate. It equals Σ False positive/Σ Predicted condition positive. See https://en.m.wikipedia.org/wiki/Precision_and_recall https://en.m.wikipedia.org/wiki/Precision_and_recall for a table of different terms.