From glitzy Las Vegas–style games at one extreme to page turners consisting of text on screens at the other, many e-learning courses ignore human cognitive processes and, as a result, do not optimize learning. In writing this book, we were guided by two fundamental assumptions: (1) the design of e-learning courses should be based on a cognitive theory of how people learn and (2) on scientifically valid research studies. In other words, e-learning courses should be constructed in light of (1) how the human mind learns and (2) experimental evidence concerning e-learning features that best promote learning. In this chapter we focus on the first assumption by describing how learning works and how to help people learn. In this edition, we have added a rationale for considering how learning works and a more detailed description of how instruction can be designed in light of obstacles to learning. Based on cognitive theories of how people learn, we focus on three instructional goals—minimize extraneous processing (cognitive processing unrelated to the instructional goal), manage essential processing (cognitive processing to mentally represent the key material), and foster generative processing (deeper processing). The following chapter (Chapter 3) focuses on the second assumption by giving the rationale for evidence-based practice and by providing guidance for how to identify and use good research.