MAP

Synonyms

Mean average precision

Definition

The Mean Average Precision (MAP) is the arithmetic mean of the average precision values for an information retrieval system over a set of n query topics. It can be expressed as follows:

$$ \mathrm{MAP}=\frac{1}{n}{\displaystyle \sum_n{\mathrm{AP}}_n}\ $$

where AP represents the Average Precision value for a given topic from the evaluation set of n topics.

Key Points

The Mean Average Precision evaluation metric has long been used as the de facto “gold standard” for information retrieval system evaluation at the NIST Text Retrieval Conference (TREC) [1]. Many TREC tracks over the years have evaluated run submissions using the trec_evalprogram, which calculates Mean Average Precision, along with several other evaluation metrics. Much of the published research in the information retrieval field over the last 25 years relies on observed difference in MAP to draw conclusions about the effectiveness of a studied technique or system relative to a...