Marcel Caraciolo says:
In this post I will introduce three metrics widely used for evaluating the utility of recommendations produced by a recommender system : Precision , Recall and F-1 Score. The F-1 Score is slightly different from the other ones, since it is a measure of a test’s accuracy and considers both the precision and the recall of the test to compute the final score.
Recommender systems are quite common and you are likely to encounter them while deploying topic maps. (Or you may wish to build one as part of a topic map system.)