Accurate polling requires the demographic breakdown of a survey to closely resemble the same breakdown for the population you are trying to measure. By beginning their surveys by asking for the “second oldest woman in the household” or some other criteria, traditional pollsters can manipulate their respondents during a poll in order to reach quotas for demographic groups like gender, race, age, etc. IVR polling does not allow PPP to set quotas beforehand, instead we have to work with the data after our survey. To achieve relatively accurate demographic breakdowns we employ weighting schemes.
Our first step in weighting is to survey more than enough people. This allows us to then be able to randomly reject individual surveys from demographics that are overrepresented. For example, in our polling more women answer relative to men, and not enough African-Americans answer our surveys. Our random selection eliminates any potential bias from the rejections, plus it functions like a quota, only after the fact.
PPP also employs a mathematical weighting scheme that assigns a weight based on each demographic. For example, if a survey is 82% white and 13% black, but needs to be 77% white and 17% black, the weighting formula can fix the imbalance mathematically. We always try to get our numbers as accurate as possible, and our end results are available for all to see and scrutinize. Read more about PPP’s track record.