Most common effectiveness measures for information retrieval systems are based on the assumptions of binary relevance (either a document is relevant to a given query or it is not) and binary retrieval (either a document is retrieved or it is not). In this paper, we describe an information retrieval effectiveness measure named ADM (Average Distance Measure) that questions these assumptions. We compare ADM with other measures, discuss it from a conceptual point of view, and report some experimental results. Both conceptual analysis and experimental evidence demonstrate ADM adequacy in measuring the effectiveness of information retrieval systems.
