PIAAC evolved from two previous international literacy surveys: the International Adult Literacy Survey (IALS), conducted between 1994 and 1998, and the Adult Literacy and Life Skills Survey (ALL), conducted between 2002 and 2006. With the first round of data collection, PIAAC sought to ensure continuity with these previous surveys, provide information regarding change in the distribution of skills over the years, extend the skill being measured by including problem solving in technology-rich environments, and provide more information about individuals with low levels of competency by assessing reading component skills.

Twenty-four countries participated in Round 1 of the Survey of Adult Skills (PIAAC), with data collection taking place from August 1, 2011, to March 31, 2012, in most countries. Nine countries took part in Round 2 of the assessment, with data collection taking place from April 2014 to the end of March 2015, and five new countries will be taking part in Round 3, which will take place from 2016 to 2019.

In total, around 250,000 adults, representing 815 million adults aged 16 to 65, were surveyed in over 40 countries and sub-national regions, along with all of Canada’s provinces and territories, in the official language(s) of the countries in the first two rounds of the study.

Available data and documentation as part of the survey include:

  • Frameworks (for the background questionnaire, literacy, numeracy, and PS-TRE)
  • Background questionnaires
  • Technical reports
  • Proficiency level descriptions
  • Public Use Files (PUF codebooks, variables, and values)
  • International reports, national reports

Technical reports

Proficiency level descriptions

Besides of presenting key facts about the Survey of Adult Skills, this document provides the detailed explanation of the proficiency levels in the three domains assessed in the Survey: literacy, numeracy and problem solving in technology-rich environments, as well as the corresponding proficiency score.

  • View or download proficiency levels descriptions for:
    • Literacy
    • Numeracy
    • PS-TRE
For more information and to access any items part of this list, please go to “accessing the data.