METHODOLOGY
Online interviews were conducted from 10/20 to 10/22 2014 among a nationally representative sample of 1,092 U.S. adults, aged 18 and older.
The questionnaire averaged 17 minutes to complete with the focus on self-reported behavior and attitudes toward sleep. Where appropriate, answer choices were rotated, eliminating potential biases from the sequencing of answers. The survey was administered to any person aged 18 and older except those who indicated that they are in the media business.
Quotas were set for: gender, age breaks, household income breaks, Census regions, African Americans and Hispanics.
These were further refined by weighting: gender, age, region and race/ethnicity to their exact Census proportions.
The dataset was cleaned to eliminate straight-liners, speeders and respondents who gave highly inconsistent answers on key questions; 209 respondents were removed from the initial dataset.
The study was fielded by Survey Sampling International, an independent research company based in Connecticut. Survey Sampling provided the online sample.