Gallup interviews 1,000 U.S. adults each day regarding various political, economic, and well-being topics as part of Gallup Daily tracking, which includes the Gallup-Sharecare Well-Being Index. The interviews are conducted by telephone 350 days per year. The results are reported in daily, weekly, and monthly averages and in Gallup.com stories.
The survey methodology involves a dual-frame telephone sampling approach. Each sample of national adults includes a minimum quota of 50% cellphone respondents and 50% landline respondents, with additional minimum quotas by time zone within region. Landline and cellular telephone respondents are selected using random-digit-dial methods. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Gallup uses a multicall design to reach respondents not contacted on the initial attempt. Gallup Daily tracking includes interviews in Alaska and Hawaii, and Spanish-language interviews for Spanish-speaking respondents.
Samples are weighted daily to account for unequal selection probability, nonresponse, and double coverage of landline and cellphone users in the two sampling frames. They are also weighted to match the national demographics of gender, age, race, Hispanic ethnicity, education, region, population density, and phone status (cellphone only/landline only/both, and cellphone mostly). Demographic weighting targets are based on the most recent Current Population Survey figures for the aged 18 and older U.S. population. Phone status targets are based on the most recent National Health Interview Survey. Population density targets are based on the most recent U.S. census. All reported margins of sampling error include design effects for weighting.