In every U.S. presidential election since 1948, the American National Election Studies (ANES) has conducted pre- and post-election surveys of a large representative sample of American voters. ANES participant interviews looked different in 2020 than they did in the past; the COVID19 pandemic made traditional face-to-face interviews impractical and risky. The study team began planning for the extraordinary circumstances in March, without any idea what the conditions would be when interviews began in August. The team pivoted nimbly to redesign the study even as the onset of data collection approached.
The majority of interviews in 2020 were completed as web surveys, some following an online format similar to one used in 2016, and others using an innovative mixed-mode design. Respondents to the mixed-mode surveys were randomly assigned either to complete the questionnaire by themselves online, or to take the survey with a live interviewer via a Zoom video link. Few surveys conduct live video interviews, but the ANES study team felt that it was critical to explore the use of this technology as a potential means of balancing issues of cost, continuity, and data quality.
To answer online surveys, respondents must have reliable access to the Internet and comfort using computers. Under normal circumstances, people without access to computers or the Internet in their homes can gain access in public settings like libraries or at their workplace. With many of these places closed due to the pandemic, online access became a bigger challenge. In mixed-mode cases where it was difficult to complete a web or video interview, interviewers contacted the respondents to secure a phone interview. Providing phone interviews helped the team strengthen sample quality by reaching respondents without access to the Internet as well as those who are less comfortable using computers.
Data collection for the 2020 surveys, out of necessity, departed significantly from the practices of the past 70 years of the ANES. The study team will continue to monitor and address the implications of these changes. In the end, the team was pleased to field a very high quality survey with relatively high response rates, thoroughly vetted questions, and the largest sample in the history of ANES.
Pre-election interviews began in August 2020. The pre-election questionnaire is available on the ANES website. The questionnaire includes time series questions dating back to the earliest days of the ANES survey, as well as new questions that reflect more recent developments in the study of American politics. The ANES team must always be prepared to add a few questions late in the design process to capture substantial developments in the presidential campaign or American society. In 2020 the survey added questions about election integrity, urban unrest, and COVID-19, among other topics.
The investigators, ANES staff, and their survey operations partners at Westat monitored the data collection closely, in case further adjustments in procedures or sample were required. The final pre-election sample consists of over 8,200 complete or sufficient-partial interviews. This includes a reinterview panel with the respondents from the ANES 2016 Time Series. Over 2,800 respondents from the 2016 study were reinterviewed, more than three quarters of the original group.
Post-election interviews began on November 8, 2020, and will be completed on January 4, 2021. This post-election effort includes additional respondents who took part in the 2000 study of the General Social Survey (GSS). Due to the pandemic-altered timing of the GSS data collection, it was not possible to interview these individuals prior to the election. However, these respondents completed nearly all of the ANES post-election interview, plus almost ten minutes of critical questions that appeared on the ANES pre-election interview, and several additional questions suggested by the GSS team.
ANES staff will continue to review and clean the data into the new year, including checks of respondent eligibility that may alter the final sample in modest ways. Pending this review, the team expects response rates to come in slightly below the 2016 web response rates.
Overall, despite the challenges of this past year, the ANES study team was able to gather robust data from a large probability sample of Americans, extending the longest-running, most in-depth, and highest quality survey of US public opinion and voting behavior, at a critical juncture for American society and democracy. The team will continue to share updates, here and on the ANES website, as data from this survey become available.