Methods and apparatus to perform identity matching across audience measurement systems

Abstract

Methods, apparatus, systems and articles of manufacture to perform identity matching across audience measurement systems are disclosed. An example apparatus includes a data normalizer to normalize audience measurement events corresponding to media exposure data obtained from a first audience measurement system and a second audience measurement system, a tree builder to build a k-dimensional tree based on normalized audience measurement events, a candidate identifier to calculate a distance between a query event and a first audience measurement event included in a search space in the k-dimensional tree, identify the query event and the first audience measurement event as a candidate match when the calculated distance satisfies a distance threshold, an array builder to generate metrics at an identifier-level based on a plurality of candidate matches, and a thresholder to identify an identifier mapping linking a first user identifier to a second user identifier when the metrics satisfy respective metric thresholds.