The purpose of this booklet is to document cross-national patterns of adult learning, and in particular the unequal chances to participate in adult learning. In so doing, an effort is made to identify important motivating factors for participating in adult learning. The specific objectives of the booklet are to: (1) make available the internationally comparative data on adult education to a wide audience; (2) present an overview of the extent of adult learning in a comparative perspective; (3) identify international patterns of who is and who is not participating in adult learning, including unequal chances to participate; and (4) discuss various motivating factors that can explain observed inequalities in participation, by using internationally competitive data. It is divided into three chapters. The first chapter provides a brief overview of key issues and trends in adult learning research and policy and discusses the availability of comparative data and evidence. The second chapter presents data analyses that give a comparative overview of adult learning patterns. The third and final chapter offers some conclusions and implications for research and policy. (Contains 14 tables, 2 figures, 1 box, and 2 footnotes.)