Abstract This article focuses on adults’ informal learning related to sustainability, addressing a central gap in adult education research through a combination of quantitative and qualitative methods. Drawing on data from the German National Educational Panel Study (NEPS), the authors investigate which sustainability-related learning topics adults mention in open-ended responses and in which learning contexts these topics emerge. They analyse open-ended responses of adults aged 35–75 ( N = 6,793) across four survey waves (2017–2022), covering informal learning in different contexts (trade fairs and conferences, specialist lectures, digital learning programmes and internet-based learning opportunities). Based on these responses, they developed a deductive–inductive category system that served as the basis for coding a total of 17,395 statements. Building on this, they explore the characteristics, such as sociodemographics, personality traits and generalised values, of individuals who engage intensively with ecological sustainability topics across different contexts and over time. Combining qualitative content analysis with a large-scale national survey and rich contextual data, this study provides new insights into the content and patterns of adults’ sustainability-related informal learning and discusses the practical implications for adult education.
Costa et al. (Fri,) studied this question.