NOTE: All results show percentages among all respondents, unless otherwise labeled.
This survey was conducted by The Associated Press-NORC Center for Public Affairs Research and with funding from NORC at the University of Chicago. Data were collected using AmeriSpeak®, which is a probability-based panel designed to be representative of the U.S. household population. The survey was part of a larger study that included questions about other topics not included in this report. During the initial recruitment phase of the panel, randomly selected U.S. households were sampled with a known, non-zero probability of selection from the NORC National Sample Frame and then contacted by U.S. mail, email, telephone, and field interviewers (face-to-face).
Interviews for this survey were conducted between February 11 and 14, 2016, with adults age 18 and over from the 50 states and the District of Columbia. Panel members were randomly drawn from AmeriSpeak®, and 1,042 completed the survey—814 via the web and 228 via telephone. The final stage completion rate is 30.3 percent, the weighted household panel response rate is 36.9 percent, and the weighted household panel retention rate is 93.7 percent, for a cumulative response rate of 10.5 percent. The overall margin of sampling error is +/- 3.9 percentage points at the 95 percent confidence level, including the design effect. The margin of sampling error may be higher for subgroups.
Once the sample has been selected and fielded, and all the study data have been collected and made final, a poststratification process is used to adjust for any survey nonresponse as well as any noncoverage or under- and oversampling resulting from the study-specific sample design. Poststratification variables included age, gender, census division, race/ethnicity, and household phone status. The weighted data, which reflect the U.S. population of adults age 18 and over, were used for all analyses.
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The two organizations have established the AP-NORC Center for Public Affairs Research to conduct, analyze, and distribute social science research in the public interest on newsworthy topics, and to use the power of journalism to tell the stories that research reveals.
The founding principles of the AP-NORC Center include a mandate to carefully preserve and protect the scientific integrity and objectivity of NORC and the journalistic independence of AP. All work conducted by the Center conforms to the highest levels of scientific integrity to prevent any real or perceived bias in the research. All of the work of the Center is subject to review by its advisory committee to help ensure it meets these standards. The Center will publicize the results of all studies and make all datasets and study documentation available to scholars and the public.