Compas Poll / Survey

COMPAS conducted a national, election day poll on behalf of Global Television. The advantage of election day polls over prior and subsequent polls is that they capture voters just at the time of their greatest mental focus on their decision. For this reason, their responses to questions about what motivated their vote and precisely when they made their ultimate decision have special value.

The downside of daytime polling is that respondents who are interviewed at home are not very representative of the population as a whole. When unrepresentativeness is modest, such sampling biases can be neutralized through sample weighting via statistical means. It is difficult to do so successfully when a sample is more than trivially unrepresentative, which is the case of daytime polls.

A vital way of gauging the value of responses to individual questions in a daytime poll is to compare responses using different weighting formulas, for example, weighting for age, gender, and region alone vs. in combination with weighting for education and/or occupation. Responses that vary little with a change of weighting are stable and hence highly reportable.