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History of International and National Adult Literacy Assessments

The origins of the international adult literacy assessment program, which began with the International Adult Literacy Survey (IALS) and continues with Program for the International Assessment of Adult Competencies (PIAAC), lie to a large extent in the pioneering work of national adult literacy assessments undertaken in the United States and Canada in the early 1990s.

In the United States, the National Adult Literacy Survey (NALS) was conducted in 1992 by the National Center for Education Statistics (NCES). NALS assessed a nationally representative sample of adults residing in households, as well as a sample of adults in prisons. More information about NALS can be found here.

In 2003, NCES conducted its largest household assessment of adult literacy skills in the United States: the National Assessment of Adult Literacy (NAAL). NAAL sampled adults representing the entire population of U.S. adults residing in households and also sampled adults representing the population in federal and state prisons. NALS and NAAL each presented a snapshot of the condition of literacy for the U.S. population as a whole and among key population subgroups and, when looked at in combination, changes in literacy over time. More information about NAAL can be found here.

The IALS study, developed by Statistics Canada and ETS in collaboration with participating national governments, adopted and refined the NALS methodology, scales, and literacy frameworks. Twenty-two countries, including the United States, administered the IALS study in three waves between 1994 and 1998. More information about IALS can be found here.

Concurrent with the further waves of IALS data collection, Statistics Canada sponsored work on the development of a successor to IALS with the goal of measuring a broader range of adult skills than had been covered previously. The Adult Literacy and Lifeskills Survey (ALL) sought to improve on IALS by developing standards and quality assurance measures that would minimize sources of survey variability and, therefore, render the survey results more comparable. Eleven countries, including the United States, administered the ALL study in two waves between 2003 and 2008. More information about ALL can be found here.

PIAAC seeks to ensure continuity with these previous surveys, expand on their quality assurance standards, extend the definitions of literacy and numeracy, present the problem-solving domain to emphasize skills used in technology-rich environments, and provide more information about individuals with low levels of literacy by assessing reading component skills.

Overview of Previous International and National Assessments of Adult Skills
Assessment Year(s) U.S. Sample Size Population Domains National/International Survey
National Adult Literacy Survey (NALS) 1992 Approximately 26,000, including more than 1,100 inmates and the approximately 1,000 adults surveyed in 12 states Adults 16 and older, in households and prisons Prose literacy, Document literacy, Quantitative literacy National; in addition,12 states participated in the State Adult Literacy Survey (SALS) to report state-level results comparable to the national data
International Adult Literacy Survey (IALS) 1994–1998 Approximately 3,000 Adults 16–65, in households Prose literacy, Document literacy, Quantitative literacy International; 22 countries participated
National Assessment of Adult Literacy (NAAL) 2003 Approximately 19,700, including about 1,200 inmates, and approximately 1,000 adults surveyed in 6 states Adults 16 and older, in households and prisons Prose literacy, Document literacy, Quantitative literacy National; in addition, 6 states participated in the State Assessment of Adult Literacy (SAAL) to report state-level results comparable to the national data
Adult Literacy and Lifeskills Survey (ALL) 2003–2008 Approximately 3,400 Adults 16–65, in households Document literacy, Prose literacy, Numeracy International; 11 countries participated
Program for the International Assessment of Adult Competencies (PIAAC) 2012–2107 (Cycle I) Approximately 13,600, including about 5,000 in 2012, over 3,600 in 2014, and over 3,600 in 2017 in households, and about 1,300 inmates Adults 16–74, in households in prisons Literacy, Numeracy, Problem solving in technology-rich environments International; 39 countries participated