Effectiveness is a primary concern in the information retrieval (IR) field. Various metrics for IR effectiveness have been
proposed in the past; we take into account all the 44 metrics we are aware of, classifying them into a two-dimensional grid.
The classification is based on the notions of relevance, i.e., if (or how much) a document is relevant, and retrieval, i.e., if (how much) a document is retrieved. To our knowledge, no similar classification has been proposed so far.