The 2020 American National Election Study was conducted by the Center for Political Studies of the Institute for Social Research, at the University of Michigan. This study is part of a time-series collection of national surveys fielded continuously since 1948. The election studies are designed to present data on Americans' social backgrounds, enduring political predispositions, social and political values, perceptions and evaluations of groups and candidates, opinions on questions of public policy, and participation in political life.
The sample of the ANES 2020 Time Series Study consisted of a new cross-section of respondents that yielded 5,441 interviews in the pre-election study (a combination of Web, telephone, and video) plus 2,839 reinterviews of the 2016 panel, for a total of 8,280 interviews. Of those respondents, 7,449 also completed the post-election interview. The samples were drawn from the U.S. population of adults aged 18 and over who were eligible to vote.
For detailed information on the methodology and content of the survey, see the User Guide and Codebook at the official ANES site at the University of Michigan.