focal loss

Focal loss is a way of changing the normal way that a computer learns when it is trying to figure out if something is true or not. It helps a computer more efficiently learn which things it should pay more attention to, while ignoring the things that aren't very important. Think of it like a game of 'hot and cold': the computer starts off not knowing where the right answer is, but with each guess it gets closer and closer to the correct answer. With focal loss, it helps the computer focus on the things that will get it closer to the correct answer faster.