The Gallup-Healthways Well-Being Index tracks the well-being of U.S. residents throughout the year, interviewing no fewer than 500 U.S. adults nationwide each day, with the exception of major holidays. Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking.
Each daily sample includes a minimum quota of 150 cell phone respondents and 850 landline respondents, with additional minimum quotas among landline respondents for gender within region. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Samples are weighted by gender, age, race, Hispanic ethnicity, education, region, adults in the household, cell-phone-only status, cell-phone-mostly status, and phone lines. Demographic weighting targets are based on the March 2009 Current Population Survey figures for the aged 18 and older non-institutionalized population living in U.S. telephone households. All reported margins of sampling error include the computed design effects for weighting and sample design.
With the inclusion of the cell-phone-only households and the Spanish Language interviews, 98% of the adult population is represented in the sample. By comparison, typical landline-only methodologies represent approximately 85% of the adult population.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
Click here to download the formal methodology and Well-Being Index research report.