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by shawabawa3 247 days ago
Accuracy is a nonsense word in this context

Tests have a sensitivity (1 - percentage of false negatives) and specificity (1 - percentage of false positives)

"Accuracy" usually refers to sensitivity. If specificity is near 100% and the test is cheap/fast even low sensitivity can be good

On the other hand you could have sensitivity of 100% but the test could be useless if specificity is low and the condition is rare

2 comments

No, it is a well defined term in this context and does not refer to sensitivity.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4614595/#:~:text=Ac...

That is exactly why I gave the trivial example of an "always No" test. It has perfect specificity (zero false positives) and has accuracy corresponding to prevalence. The sensitivity is zero, however, which is the point.

The paper explains what it actually means, so it's not nonsense. See my other comment https://news.ycombinator.com/item?id=45558941 it's the area under the curve for the receiver-operating characteristic curve and 94% is extremely good.