Given this environment, one might expect that the number of questions in the Roper iPoll database on any particular topic would be the same or higher in 2020 than in 2016. However, the opposite appears to be true: in general, there are to date fewer questions from 2020 than at the same point in 2016. Why is this?
The Topic Tracker pulls its data from the Roper iPoll database, which includes only those polls that qualify for the Roper Center Longstanding Methods Collection. These polls are probability-based, utilizing random samples. If conducted by telephone, only those polls that use live interviewers are included. Registration-based and other list-based sampling is also excluded.
With costs increasing and technological barriers to reaching respondents by phone resulting in ever-lower response rates, many survey organizations have moved away from these approaches to embrace online nonprobability panels, voter-list samples, Interactive Voice Response (IVR), or other methods. Those organizations that having continued to use Longstanding Methods have in some cases decreased the frequency of their polling to reduce costs.
Roper Center has responded to these changes in public opinion research by establishing a new Recently Developed Methods Collection. Polls in this collection may use any number of different methodologies, but each must meet a very high standard of transparency, with extensive documentation of methodological approaches and other information about how the poll was conducted.
For definitions of common terms in polling methodology, see our Glossary.