• Used for recommender systems and search engines
• used mostly for information retrieval evaluations such as Humpback Whale Identification competition, where you have to precisely identify a whale and you have five possible guesses.
• In essence, when MAP@{K} is the evaluation metric, you can score not just if you can guess correctly, but also if your correct guess is among a certain number (the “K” in the name of the function) of other incorrect predictions.