Mayes argues that design decisions need to be based on clear theoretical principles, and identifies three broad perspectives on learning from which these principles can be drawn: the associative, cognitive, and situative. In a comprehensive revision of the chapter for this third edition, he summarises new evidence from the fields of artificial or machine learning, neural networks, educational neuroscience, and the study of learning on the participative web. He concludes that new advances do not validate one approach over others, but that the three approaches continue to provide complementary resources for the designer, drawing on different epistemological traditions.