Abstract: Examples to determine media impressions are disclosed. An example method includes detecting a cookie identifier established by a database proprietor at a computing device, determining an impression of media, wherein the impression occurs after the cookie identifier is established, determining a first panelist identifier associated with the impression based on the cookie identifier, determining a second panelist identifier associated with the impression based on determination of a user identity by a panelist meter associated with the computing device, and storing an adjustment factor determined by comparing the first panelist identifier and the second panelist identifier.

Abstract: Methods, apparatus, and articles of manufacture to analyze and adjust demographic information of audience members are disclosed. An example method involves generating a first model based on reference demographic data corresponding to panelists and based on second demographic data and behavioral data from a database proprietor. The second demographic data and the behavioral data correspond to ones of the panelists having user accounts with the database proprietor. The method also involves using the first model to partition the second demographic data into a plurality of nodes, each node representing a respective subset of the second demographic data. The method also involves redistributing at least some of the second demographic data between at least some of the nodes to generate a second model.