NAAL is designed to provide a national-level assessment and, for states that choose to participate in SAAL, a state-level assessment of adult literacy. To reduce both burden and cost, NAAL has selected a relatively small number of respondents within each county and/or city, as compared to the number of people it has selected within a state. NAAL has produced small area estimates which are based upon modeling. You can view state and county level estimates here.
NAAL is inherently designed to accommodate adults with disabilities since (1) it is conducted one-on-one in participants' homes, eliminating the distractions of a group test setting; and (2) adults with disabilities are given extra time to complete each question.
Also, NAAL gathers information about participants with disabilities. Interviewers collect information about when and why respondents did not fully complete the assessment questions. Additionally, the 2003 NAAL background questionnaire includes questions about learning disability diagnosis, hearing and visual impairment, and other health problems or disabilities that may impede participation in work, school, and other activities. All of this information helps researchers understand the relationship between literacy data and disabilities.
NAAL makes a number of procedural and linguistic accommodations to include data about the literacy skills of adults with limited English proficiency. Trained interviewers, some of whom are bilingual in English and Spanish, conduct the assessment through personal interviews in the respondent's home. The core screening questions and ALSA are administered orally in English or Spanish (depending on respondent's preference). While cost considerations prevent NAAL from using bilingual interviewers proficient in languages other than Spanish and English, the respondent may use an intermediary such as a family member or friend to translate the screener questions if they speak a language other than English or Spanish. (Note: The actual assessment questions are all in English, as NAAL is an assessment of English literacy within the U.S. population.)
Also, the background questionnaire includes a number of questions on a participant's language background. Such information will prove useful in identifying the relationship between an adult's language background and English literacy proficiency and fluency.