In the last decade, the field of multimedia learning emerged as a coherent discipline with an accumulated research base that had never been synthesized and organized in a handbook. The Cambridge Handbook of Multimedia Learning, first published in 2005, constituted the world's first handbook devoted to comprehensive coverage of research and theory in the field of multimedia learning. Multimedia learning is defined as learning from words (e.g., spoken or printed text) and pictures (e.g. illustrations, photos, maps, graphs, animation, or video). The focus of this handbook is on how people learn from words and pictures in computer-based environments. Multimedia environments include online instructional presentations, interactive lessons, e-courses, simulation games, virtual reality, and computer-supported in-class presentations. The Cambridge Handbook of Multimedia Learning seeks to establish what works (that is, to ground research in cognitive theory), and to consider when and where it works (that is, to explore the implications of research for practice).