The American Trends Panel survey methodology
Overview
The American Trends Panel (ATP), created by Pew Research Center, is a nationally representative panel of randomly selected U.S. adults. Panelists participate via self-administered web surveys. Panelists who do not have internet access at home are provided with a tablet and wireless internet connection. Interviews are conducted in both English and Spanish. The panel is being managed by Ipsos.
Data in this report is drawn from ATP Wave 146, conducted from April 8 to April 14, 2024. It includes oversamples of non-Hispanic Asian adults, non-Hispanic Black adults, Hispanic adults and adults ages 18 to 29 in order to provide more precise estimates of the opinions and experiences of these smaller demographic subgroups. It also included an oversample of validated 2016 and 2020 “vote switchers,” who voted for Donald Trump in 2020 but not in 2016 or who voted for Joe Biden in 2020 but not for Hillary Clinton in 2016. These oversampled groups are weighted back to reflect their correct proportions in the population. A total of 8,709 panelists responded out of 9,527 who were sampled, for a response rate of 91%. The cumulative response rate accounting for nonresponse to the recruitment surveys and attrition is 3%. The break-off rate among panelists who logged on to the survey and completed at least one item is less than 1%. The margin of sampling error for the full sample of 8,709 respondents is plus or minus 1.5 percentage points.
Panel recruitment
The ATP was created in 2014, with the first cohort of panelists invited to join the panel at the end of a large, national, landline and cellphone random-digit dial survey that was conducted in both English and Spanish. Two additional recruitments were conducted using the same method in 2015 and 2017, respectively. Across these three surveys, a total of 19,718 adults were invited to join the ATP, of whom 9,942 (50%) agreed to participate.
In August 2018, the ATP switched from telephone to address-based sampling (ABS) recruitment. A study cover letter and a pre-incentive are mailed to a stratified, random sample of households selected from the U.S. Postal Service’s Delivery Sequence File. This Postal Service file has been estimated to cover as much as 98% of the population, although some studies suggest that the coverage could be in the low 90% range. Within each sampled household, the adult with the next birthday is asked to participate. Other details of the ABS recruitment protocol have changed over time but are available upon request.
We have recruited a national sample of U.S. adults to the ATP approximately once per year since 2014. In some years, the recruitment has included additional efforts (known as an “oversample”) to boost sample size with underrepresented groups. For example, Hispanic adults, Black adults and Asian adults were oversampled in 2019, 2022 and 2023, respectively.
Across the six address-based recruitments, a total of 23,862 adults were invited to join the ATP, of whom 20,917 agreed to join the panel and completed an initial profile survey. Of the 30,859 individuals who have ever joined the ATP, 11,902 remained active panelists and continued to receive survey invitations at the time this survey was conducted.
The American Trends Panel never uses breakout routers or chains that direct respondents to additional surveys.
Sample design
The overall target population for this survey was noninstitutionalized persons ages 18 and older living in the U.S., including Alaska and Hawaii. It featured a stratified random sample from the ATP in which the following groups were selected with certainty:
- Non-Hispanic Asian adults
- Non-Hispanic Black adults
- Hispanic adults
- Adults ages 18 to 29
- Validated 2016 and 2020 voters who voted for Donald Trump in 2020 but did not vote for Trump in 2016.
- Validated 2016 and 2020 voters who voted for Joe Biden in 2020 but did not vote for Hillary Clinton in 2016.
The remaining panelists were sampled at rates designed to ensure that the share of respondents in each stratum is proportional to its share of the U.S. adult population to the greatest extent possible. Respondent weights are adjusted to account for differential probabilities of selection as described in the Weighting section below.
Questionnaire development and testing
The questionnaire was developed by Pew Research Center in consultation with Ipsos. The web program was rigorously tested on both PC and mobile devices by the Ipsos project management team and Pew Research Center researchers. The Ipsos project management team also populated test data that was analyzed in SPSS to ensure the logic and randomizations were working as intended before launching the survey.
Incentives
All respondents were offered a post-paid incentive for their participation. Respondents could choose to receive the post-paid incentive in the form of a check or a gift code to Amazon.com or could choose to decline the incentive. Incentive amounts ranged from $5 to $20 depending on whether the respondent belongs to a part of the population that is harder or easier to reach. Differential incentive amounts were designed to increase panel survey participation among groups that traditionally have low survey response propensities.
Data collection protocol
The data collection field period for this survey was April 8 to April 14, 2024. Postcard notifications were mailed to a subset of ATP panelists with a known residential address on April 8.
Invitations were sent out in two separate launches: soft launch and full launch. Sixty panelists were included in the soft launch, which began with an initial invitation sent on April 8. The ATP panelists chosen for the initial soft launch were known responders who had completed previous ATP surveys within one day of receiving their invitation. All remaining English- and Spanish-speaking sampled panelists were included in the full launch and were sent an invitation on April 9.
All panelists with an email address received an email invitation and up to two email reminders if they did not respond to the survey. All ATP panelists who consented to SMS messages received an SMS invitation and up to two SMS reminders.
Data quality checks
To ensure high-quality data, the Center’s researchers performed data quality checks to identify any respondents showing clear patterns of satisficing. This includes checking for whether respondents left questions blank at very high rates or always selected the first or last answer presented. As a result of this checking, three ATP respondents were removed from the survey dataset prior to weighting and analysis.
Weighting
The ATP data is weighted in a multistep process that accounts for multiple stages of sampling and nonresponse that occur at different points in the survey process. First, each panelist begins with a base weight that reflects their probability of selection for their initial recruitment survey. These weights are then rescaled and adjusted to account for changes in the design of ATP recruitment surveys from year to year. Finally, the weights are calibrated to align with the population benchmarks in the accompanying table to correct for nonresponse to recruitment surveys and panel attrition. If only a subsample of panelists was invited to participate in the wave, this weight is adjusted to account for any differential probabilities of selection.
Among the panelists who completed the survey, this weight is then calibrated again to align with the population benchmarks identified in the accompanying table and trimmed at the 2nd and 98th percentiles to reduce the loss in precision stemming from variance in the weights. This trimming is performed separately among non-Hispanic Black, non-Hispanic Asian, Hispanic and all other respondents. Sampling errors and tests of statistical significance take into account the effect of weighting.
The following table shows the unweighted sample sizes and the error attributable to sampling that would be expected at the 95% level of confidence for different groups in the survey.
Sample sizes and sampling errors for other subgroups are available upon request. In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.
Dispositions and response rates
Validated voters
Members of Pew Research Center’s nationally representative American Trends Panel were matched to public voting records from national commercial voter files in an attempt to find records for voting in the 2016 and 2020 general elections. Validated voters are citizens who told us in a post-election survey that they voted in a given election and have a record for voting in that election in a commercial voter file. Nonvoters are citizens who were not found to have a record of voting in any of the voter files or told us they did not vote.
In an effort to accurately locate official voting records, up to three commercial voter files were searched for each panelist. The number of commercial files consulted varied by when a panelist was recruited to the ATP. Three files were used for panelists recruited in 2022 or before, while one file was used for panelists recruited in 2023. Altogether, files from four different vendors were used, including two that serve conservative and Republican organizations and campaigns, one that serves progressive and Democratic organizations and campaigns, and one that is nonpartisan.
Additional details and caveats about the validation of votes in 2016 and 2020 can be found in these methodological reports:
© Pew Research Center, 2024
