Education 20 self-directed learning 8 Self-directed learning 5 human 5 Adult education, continuous learning 4 Educational strategies & policy 4 Learning 4 problem based learning 3 Adult learners 2 Article 2 Higher & further education, tertiary education 2 History 2 Humans 2 Teacher training 2 Teaching skills & techniques 2 Universities 2 adult 2 curriculum 2 female 2 human experiment 2 male 2 medical education 2 performance 2 21st-century learners 1 3D animation 1 Action research 1 Augmented Reality 1 Augmented reality 1 Augmented reality vs. virtual reality 1 Biopsy 1