Data collection for the main NAAL study and concurrent state assessment, SAAL, was conducted in 2003 using in-person household interviews. Over 18,000 adults participated, selected from a sample of over 35,000 households that represented the entire U.S. household population age 16 and over—about 222 million Americans (U.S. Census Bureau, Current Population Survey 2003). In addition, approximately 1,200 inmates from 107 federal and state prisons were assessed in early 2004 for the prison assessment, which provides separate estimates of literacy levels for the incarcerated population. View information on 1992 NALS data collection.
All household participants received an incentive payment of $30 in an effort to increase both the representativeness of the sample and the response rate. Black and Hispanic households were oversampled at the national level to ensure reliable estimates of their literacy proficiencies. Special accommodations were made for adults with disabilities or with limited English proficiency.