The 2023 Survey of Adult Skills, a product of the OECD Programme for the International Assessment of Adult Competencies (PIAAC), provides a comprehensive overview of adults’ literacy, numeracy and adaptive problem-solving skills ? skills that are fundamental for personal, economic and societal development. For the first time, the 2023 Survey measured social and emotional skills of participating adults, using the BFI-2 inventory based on the Big Five taxonomy. This report provides a detailed account of the psychometric properties of the information collected with this instruments. In particular, it discusses whether such measures of social and emotional skills, collected from adults‘ self-reports, can be compared across different countries and cultural contexts and provide recommendations for how the resulting variables should be used in analysis.