ELI5: f-score

An F-score is a single score that tells you how well you did at finding all the right things without accidentally picking up the wrong things.

Imagine you are in your messy bedroom and your mom asks you to pick up all your red building blocks.

To see how well you did, we look at two things:

• Precision (Being careful): Did you only pick up red blocks? If you picked up 10 red blocks and 5 green socks by mistake, your precision is not very good because you grabbed the wrong things.
• Recall (Finding everything): Did you find all the red blocks in the room? If there were 20 red blocks hidden under the bed and you only found 10, your recall is low because you missed half of them.

The F-score combines both into one single grade:

• If you quickly grab everything on the floor (getting all the red blocks, but also shoes, books, and socks), you get a bad F-score because you were messy.
• If you only pick up one single red block and stop because you are afraid of grabbing the wrong thing, you also get a bad F-score because you left all the others behind.
• If you find almost all the red blocks and leave the socks alone, you get a great F-score!