Adult education, as a field of research, policies and practices, is characterised by diversity (^{Fejes & Nylander, 2019}; ^{Finger & Asún, 2001}; ^{Foley, 2004}). Thus, this scientific domain has come to be defined as heterogeneous, pluralistic and fostering interdisciplinarity while also being considered a weak field (^{Rubenson & Elfert, 2019}). Such diversity may be observed when analysing both the national and regional policies of different countries, or taking the policy role of international (governmental and non-governmental) organisations, aims established, programs launched, etc., into consideration. In fact, adult education policies have been marked by different perspectives, whereby lifelong learning has gained importance. This diversity is also mirrored in the discussion of practices, reflecting for instance the impact of geography and different parts of the world on adult education understandings. The development of practices leads to outcomes involving a variety of projects and activities, a broad range of participants including both adult learners and educators, bringing together formal, non-formal and informal activities and projects, aims, kinds of initiatives implemented, organisations implementing programs, etc. As a result of this diversity, fragmentation arises when considering values, education approaches, pedagogical methods and evaluation, as well as the settings where such practices take place. Light is shed upon the diverse, heterogenous and simultaneously weak nature of adult education, especially when the research and discussion of empirical data are at stake.

The diversity that characterises adult education carries complexity (^{Sava & Novotny, 2016}), namely when a comparison is achieved among different countries and regions of the world. In research, comparison has occupied a relevant role, stressing not only the differences but also the common features to be found: in policies, promoted by international and national governmental and non-governmental organisations, as well as governmental and public authorities, fostering lifelong education or lifelong learning (^{Salling Olesen, 2001}) and/or in the transition from the (adult) education (and training) system to the labour market; and in practices, such as in teaching and learning, as in higher education, or other settings such as formal, non-formal and informal adult education projects and activities.

Therefore, different themes may be addressed when discussing adult education. The diversity can also be observed when reading this special issue. The articles in this issue refer to temporal matters, recognition of prior learning, (adult) education system governance, the link between (adult) education institutions and the insertion of young people and adults in the labour market, citizenship education, local and community education and teaching and learning methods in higher education. The aim of this thematic issue of Sisyphus is to contribute to an understanding of diversity and complexity when comparison-based research is at stake, focusing on policy and practices developed in different parts of the world. The articles in this issue are the outcome of the lively discussion held in the INTALL Adult Education Academy, promoted by the University of Würzburg, at the peak of the COVID-19 pandemic, which had a significant impact on people's lives, particularly those attending this educational initiative. Attended by more than 60 students and 20 teaching staff members of higher education institutions from 5 continents in February 2021, the INTALL Adult Education Academy 2021 was a significant event to reflect critically on adult education within a comparative scope of education, at a time when a public health emergency constrained mobility and face-to-face teaching.

The seven articles included in this issue focus on a wide variety of subjects, are supported by different theoretical approaches and follow different empirical strategies. The first three articles debate adult education policies, highlighting different issues. The first article, entitled “Participation and Learning Through the Lens of Transnational Comparative Studies: Gender Facets and Temporal Constraints”, by Sabine Schmidt-Lauff, Carmel Berendi and Meta Brečić-Ločičnik, seeks to discuss the meaning of adult education in Slovenia and Hungary, focusing on temporal and gender issues in terms of participation. The collected data includes secondary data and interviews conducted with adult learners. The interviews made it possible to identify and analyse engagement and quality of time when joining professional-work related adult education programs and their liberal education counterparts. The second article, “Toward a Convergence or Divergence of Adult Learning and Education Policies? Recognition of Prior Learning in Germany and India”, by Borut Mikulec, Shalini Singh, Jan Schiller, Devaraj Balappagari and Syed Tauseef Ahmad Tirmize, discusses the influence of international governmental organisations on adult learning and education policies, with particular reference to the recognition of prior learning, following the world culture theoretical approach. Based on documental analysis, the article concludes on the convergence in adult learning and education policies for recognition of prior learning of the selected international governmental organisations (the European Union, UNESCO and the International Labour Organisation) and on divergences when policies implementation is considered. The third article, “Network Governance in Adult Education: An International Comparison of Network-Focussed Political Strategies for the Provision of Adult Education in Italy, Nigeria, and Germany” by Jörg Schwarz, Jessica Kleinschmidt, Francesca Lasi, Fatima Ibrahim Muhammad and Success Ayodeji Fasanmi, is devoted to the analysis of governance networks in Italy, Nigeria and Germany. Based on documental analysis, the description of existing adult learning and education networks (State dependant, non-profit and profit-making related), their goals, actors/stakeholders involved, practices and relationships established among them is under discussion. The conclusions show how the network governance in the selected countries is linked to international and national policies and to historical traditions and institutions in adult learning and education at different levels (national and regional).

The fourth and fifth articles, entitled “The Dimension of Policies to Foster Employability in Higher Education”, by Vanna Boffo, Letizia Gamberi, Anike Odusanya and Reem Akkeila, and “Higher Education Employability Programmes and Experiences: A Comparative Analysis of Italy, Nigeria and Palestine”, by Glenda Galeotti, Debora Daddi, Oyekunle Yinusa and Abdallah Al-haddad focus on (international and) national policies concerning higher education and the transition of students to the labour market, highlighting the aims and actors’ perspectives involved. Based on documental analysis, the discussion found in the fourth article stresses the disconnections among higher education policies and offers and labour market policies and stakeholders. The fifth article, based also on documental analysis, highlights the diversity of higher education contexts and systems but with a focus on the commonalities and strengths of the programs offered in different countries. These commonalities include the programs' development of employability skills and entrepreneurship skills.

The final two articles debate the variety of practices implemented within community adult learning and education settings and those in higher education institutions prior to and during the onset of the pandemic in 2020. Based on documental analysis, the article “Local Experiences and Global Commitments in Citizenship Education and Adult Learning in Communities: Comparative Perspectives on Austria, Germany, Hungary and Slovenia”, by Heribert Hinzen, Carina Klement, Jaka Klun and Balázs Németh, highlights the influence of UNESCO in valuing the variety of citizenship education and community spaces and programs to be found in the different countries selected for the article’s debate. The article entitled “A Comparative Consideration of Innovative Digital Teaching/Learning Methods Pre-and Post-Pandemic in Two Universities in Italy and Nigeria”, by Tewo V. Bakare, Helen Opara, Concetta Tino and Monica Fedeli, discusses the gaping chasm between traditional and modern/technology-based methods of teaching/learning in the higher education institutions of the selected countries. Based on documental analysis and direct observation, the article stresses the challenges posed by the pandemic for teaching/learning and the long road ahead when thinking and developing distance and online education and learning in universities are at stake.