The first volume in Routledge#xE2;#xAC;"s new Interdisciplinary Approaches to Educational Technologyseries, Foundations of Educational Technologyis an introductory textbook for students enrolled in Educational Technology Masters and PhD programs. It focuses on fundamental characteristics that cut across users, contexts, and settings, considers the underlying assumptions of the field, introduces the relevant theories on which practice has been developed, and discusses the kinds of professional activities graduates are likely to engage in. This text provides students with engaging exercises and activities that contribute to their professional growth, using these four pedagogical features: TELL: Presentations and directions to major sources of information and resources. ASK: Activities that encourage students to critique applications and share their individual interpretations. SHOW: Activities demonstrate the application of key concepts and complex skills with appropriate opportunities for learner responses. DO: Learners apply key concepts and complex skills while working on practice assignments and/or projects for their electronic portfolios.