ActivEpi WebActivEpi Web, is an electronic textbook for teaching epidemiology, available free on-line. This unique instructional tool contains 15 lessons (chapters) covering the full range of core epidemiology concepts. Each lesson has a full range of learning activities, including narrated instructional expositions, interactive study questions within expositions, interactive short quizzes, exercises using computer software to analyze data, homework exercises, plus materials for instructors (PowerPoint presentations, answers to homework exercises, and exam questions). From David G. Kleinbaum, epidemiology and biostatistics textbook author.