The International Survey of Adult Skills (ISAS) is a product of the Programme for the International Assessment of Adult Competencies (PIAAC) led by the Organisation for Economic Co-operation and Development (OECD). Northern Ireland participated along with 24 OECD countries and sub-regions. It assessed the proficiency of adults aged 16-65 in three information processing skills which the OECD regards as essential for full participation in the knowledge-based economies and societies of the 21st century. The three areas of proficiency assessed were ‘Literacy’; ‘Numeracy’ and ‘Problem solving in technology-rich environments’(PSTRE).