Critical thinking in the context of adult learning through PBL and e-learning: A course framework

•Critical thinking (CT) in non-formal education is underexplored in formal research.•Higher education does not guarantee solid students’ CT development.•CT courses adapting ill-structured problems can be potent to boost adults’ CT.•Problem-based learning and online learning suit adults’ CT systematic cultivation.•Learning flexibility and intrinsic motivation are guiding principles for lifelong CT learning. Critical thinking (CT) is increasingly recognized in higher education and industry as an important set of skills and dispositions that citizens should possess in 21st-century society. Particularly, CT is nowadays overwhelmingly required in industry since it determines how well workers will perform their tasks or solve work-related problems. Nevertheless, there is a significant mismatch between the demand for CT and its supply, with higher education failing to meet the latter. Open courses outside formal education may contribute to bridging this gap. When it comes to adult learners in the non-formal education context, CT teaching and learning differ from other traditional settings and audiences, and the field is underexplored. This literature review aimed at synthesizing criteria to promote CT in the context of adult education focusing on problem-based learning (PBL) and e-learning. Two leading principles play a central role in a CT development model in adult education: intrinsic motivation (inner condition) and learning flexibility (outer condition). The former concerns the learner, while the latter concerns the learning arrangement. Although self-learning is an important alternative, which has been widely practiced in adult learning, collaborative learning cannot be dismissed for effective CT development in adults. Interestingly, ill-structured problems in the frame of an integrative PBL approach seem promising for successful systematic endeavors to unlock adults’ CT potentialities, inside or outside the formal education system. And online learning can assist with this goal in particular ways. Implications for CT teaching, learning, and course design in adult education are discussed.