In the world of educational and psychological assessment, few endeavors are as challenging or as rewarding as the development of instruments that accurately measure social and emotional skills. The OECD's Study on Social and Emotional Skills (SSES) represents a monumental step in this field, with the creation of the SSES Inventory – an instrument crafted through a global, multidisciplinary effort. This manuscript delves into the intricate process and the significant outcomes of this landmark study, as detailed in the comprehensive account of its development.At the heart of the SSES study lies a rigorous instrument development process, tailored to assess 15 social and emotional skills across 45 scales. This expansive project marshaled the collective expertise of 15 international research teams and engaged more than 150,000 participants-students, parents, and teachers. Its reach spanned eleven cities globally, underscoring the universal importance of these skills. With the coordination of over a thousand professionals, including project managers, researchers, translators, and data analysts, the process was a mosaic of cultural and methodological diversity, aiming for an assessment tool of unparalleled scope and precision.Initially grappling with 380 assessment items, the teams' methodical analysis and meticulous refinement culminated in the selection of the most robust 120 items, some unaltered and others slightly adapted. The multi-faceted approach merged quantitative and qualitative research methodologies, yielding a harmonious synthesis of data and insights. This approach ensured that the resulting scales were not only reliable and valid but also resonant across different cultures, languages, and educational contexts.The book sheds light on the SSES Inventory's performance along the various stages of its empirical testing. The instrument demonstrated remarkable versatility, adapting to the developmental stages of students beginning from the age of ten. One of the key highlights was the Inventory's triangulated approach, utilizing feedback from students, parents, and teachers to enrich the data and enhance scale validity.As Kankaraš et al. (2019) indicate, the triangulation not only solidifies the SSES Inventory as a multifaceted measure but also underscores the value of gathering diverse perspectives. The Inventory's structure allows for the application within individual respondent groups, yet the most comprehensive picture emerges when the scales are administered collectively to students, parents, and teachers.The book concludes by emphasizing the SSES Inventory's significance as a psychometrically sound tool for measuring the social and emotional skills of youths aged 10 to 18. The study's implications extend far beyond the academic domain, signaling potential applications in policy-making, educational interventions, and cross-cultural understandings of student development. The SSES Inventory stands as a testament to the collaborative spirit of international research and the pursuit of nuanced, culturally competent assessment methods in the evolving landscape of social and emotional learning.
