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Survey Methods The USC Dornsife/LA Times Presidential Election "Daybreak" Poll is part of the Understanding America Study (UAS) at the University of Southern California's Dornsife Center for Economic and Social Research. It is being conducted in partnership with the Jesse M. Unruh Institute of Politics and the Los Angeles Times. The team responsible for the Daybreak Poll four years ago developed the successful RAND Continuous Presidential Election Poll, which was based on the same methodology. The Daybreak Poll is based on an internet probability panel survey. Daybreak Poll members are participants in the ongoing UAS internet probability panel of about 4500 U.S. residents who were randomly selected from among all households in the United States. Members of recruited households that did not have internet access were provided with tablets and internet service. The UAS panel is still growing. We project it will reach about 6000 members in the coming months. More than 3200 UAS panel members so far (July 2016) have agreed to participate in answering questions about the election, and we expect that number will increase over time. Each day, 1/7th of those who have agreed to participate (more than 400 per day) are invited to answer three predictive questions: What is the percent chance that... (1) you will vote in the presidential election? (2) if you were to vote, you will vote for Clinton, Trump, or someone else (percentages add to 100) and (3) Clinton, Trump or someone else will win (percentages add to 100). The order of the candidates in the questions is randomized so that about half of the respondents see Clinton as the first choice and half of the respondents see Trump as the first choice. Each night, Daybreak Poll results are weighted to match demographic characteristics (such as race and gender) from the U.S. Census Current Population Survey, and aligned to the 2012 presidential election outcome using how respondents tell us how they voted in that election. Then the latest results, averages of all of the prior week’s responses, are posted online at https://election.usc.edu and on the LATimes.com Politics site shortly after midnight. In particular, to obtain the values shown in the election forecast chart, we weight each respondent's likelihood of voting for a candidate with their likelihood of voting in the presidential election. Next we calculate the mean of that number for all respondents during the last 7 days, taking into account respondent level weights based on demographics and past voting behavior. This is the estimated fraction of the population that will vote for the candidate. The graph shows the estimated fraction of the votes that a candidate will get, which is computed by dividing the estimated fraction of the population that will vote for the candidate by the estimated fraction of the population that will vote for any candidate. The latter is analogously obtained as the weighted mean of the respondents' likelihood of voting in the presidential election. To find out more about what lies behind the vote, each week we also ask respondents one or two extra questions about their preferences and values. Links to documents detailing question text, sample sizes, response rates and other information for these separate surveys are provided in the detailed information section below, linked to stories or press releases where the results were disseminated. The Daybreak Poll began on July 4, 2016, and will run through the November election. More information about UAS panel methodology, the panel management and survey software we developed, or our publicly available datasets are available in the links here or at the UAS site (https://uasdata.usc.edu). For other questions, or to inquire about how you can conduct surveys with the UAS panel, contact us. Summary of links to more detailed information about the UAS Panel and the Daybreak Poll UAS Panel Recruitment UAS Panel sampling UAS Panel Weighting (pdf) Details of weighting the Daybreak Poll Available soon Screen shots of the 3 weekly vote questions (note order of candidates is randomized) Detailed survey methods pages for stories and releases based on additional questions Frequently Asked Questions Q: Do you use a likely voter model? A: No, the respondents provide us with their own subjective probability of voting and we use that to weight their responses. Q: Who is eligible to participate in the Daybreak poll? A: Any US citizen 18 and older Q: How does UAS select respondents within a household? A: All household members 18 and older are invited to participate Relevant references for the Daybreak Poll's probabilistic approach to election estimation ✝ Delavande, Adeline, and Charles F. Manski. 2010. Probabilistic polling and voting in the 2008 presidential election: Evidence from the American Life Panel. Public Opinion Quarterly 74:433–459. doi: 10.1093/poq/nfq019 Gutsche, T. L., Kapteyn, A., Meijer, E., & Weerman, B. (2014). The RAND Continuous 2012 Presidential Election Poll. Public Opinion Quarterly, 78, 233–254. doi: 10.1093/poq/nfu009 Kapteyn, A., Meijer, E., & Weerman, B. (2012). Methodology of the RAND Continuous 2012 Presidential Election Poll (Working Paper No. WR-961). RAND Corporation. doi: 10.2139/ssrn.2146149 ✝Daybreak Poll methodology differs from the methods described in these references in a few ways: The sample continues to grow so sample size will increase as election day nears. In relation to the growing sample size, weights are applied daily to create rolling 7 day averages, and we are using improved standard error calculations (survey bootstrap with replication weights).