1 - 4 October 2020
A sample was selected from the general smartphone audience. Participants were invited to take part in the survey by showing them adverts in mobile apps. This method can be described as river sampling. The proportion of respondents recruited in a particular app is determined by the demographic of its users. This allows for the collection of representative samples.
Data was weighted to be nationally representative in terms of age, gender, education, race, geographical region (census division), and NCHS urban/rural community type, using data from the Census Bureau's American Community Survey (ACS), as well as 2016 Presidential election vote (or non-vote). Targets for 2016 vote were calculated using results from the Federal Election Commission, population totals from ACS and mortality data from the National Centre for Health Statistics.