An example includes generating panelist-user data based on reference demographic information and self-reported demographic information, the reference demographic information and the self-reported demographic information corresponding to audience members of an audience member entity panel that are also registered users of a database proprietor, the reference demographic information from a panelist database of an audience measurement entity, and the self-reported demographic information from a user database of the database proprietor; generating a first training model and a second training model, the first training model based on a first portion of the panelist-user data, the second training model based on a second portion of the panelist-user data; selecting the first training model based on outputs of the first and second training models; and generating a third model by making an adjustment to a demographic category of the first training model, the third model to adjust third demographic information.