Generalised Differential Model (GDM)
Arie den Boon
The Generalised Differential Model (GDM) quantifies the short-term effects of different media and creative executions on attitudes, knowledge, and behaviour.
If we know who has had Opportunity To See (OTS) during the campaign, and who has not, we can calculate differences in effects (impact) between these two groups. This impact can be calculated for any medium, combination of media or creative approach. But there is one problem with this comparison: the two groups may have different characteristics. In particular, the exposed group may contain more heavy media users, and they may also be...