“The truth is rarely pure and never simple,” Oscar Wilde famously pointed out. In the audience measurement business a less famous British commentator, Rodney Harris, noted in the 1980s that “Media research is not designed to find out the truth. It is a treaty between interested parties.”
Certainly, if by truth we mean perfection, then audience measurement falls down. There are no perfect audience numbers; all are estimates. Short of interviewing everybody in the population and achieving error-free recall or tracking of behaviour, all measurement systems are imperfect.So we employ statistical techniques to help us. Four stand out: sample weighting, ascription, data fusion and modelling.