How to interpret ROC plot !ROC plot In the above plot you have true positives (y - axis), plotted against false positives (x - axis). I've read the wikipedia page on ROC curves but I just don't get it. What does the graph shown above tell me?

It says you've got yourself one heck of a good test! It's saying that even at 100% specificity (no false positives!), you're also getting almost 100% sensitivity (no false negatives!).

This may help: Sensitivity vs Specificity