The whole sentence is
We show that this approximation, when coupled with an active learning
strategy, is fast but accurate.
is there a not missing before accurate? Or is the meaning fast and accurate?
Learn English – What does fast but accurate mean
phrases
Best Answer
Sometimes, doing things faster implies that something is being sacrificed, for example accuracy. The sentence you posted says that the approximation is fast, but it does not suffer from reduced accuracy.
Fast and accurate would mean essentially the same thing, but the way it was phrased emphasizes that accuracy is not compromised, contrary to what might be expected.