The National Assessment of Adult Literacy (NAAL) assessed the English literacy of adults in the United States. Samples include a household sample, with respondents greater than 16 years of age, and a prison sample, with respondents greater than 16 years of age and incarcerated in either state or federal prison. Assessment measures include prose, document, quantative, and health literacy scales. Background data included: general and language background, educational background and experiences, political and social participation, labor force participation, literacy practices, job training and skills, demographic information, family literacy, and household income.
A cluster sampling process was employed, which involved random selection of counties, smaller area segments, household units, and finally eligible individuals.