Suppose we are playing a word game: I think a few words and you have to guess them.
As usually you will ask me some questions, identify the subject and try to guess. A possible end of the game is:
- I think: rabbit, carrot, orange.
- You try: dog, carrot, peach, orange.
We can define 2 quantities to synthesize how good you are as this game:
- precision: is the number of correct guess over the number of tries = 2/4
- recall: is the number of correct guess over the number of words to guess = 2/3
It’s easy to see that this two numbers are somehow in competition.
