In this tutorial we present a formal account of evaluation metrics for three of the most salient information related tasks: Retrieval, Clustering, and Filtering. We focus on the most popular metrics and, by exploiting measurement theory, we show some constraints for suitable metrics in each of the three tasks. We also systematically compare metrics according to how they satisfy such constraints, we provide criteria to select the most adequate metric for each specific information access task, and we discuss how to combine and weight metrics.
