This Companion Textbook supplements the ActivEpi CD-ROM, sold separately. The ActivEpi CD-ROM provides a multimedia presentation of concepts, commonly taught in an introductory epidemiology course. ActivEpi mixes a full array of media to motivate, explain, visualize and apply epidemiological concepts. Virtually all of the material on the ActivEpi CD-ROM is included in the Companion Textbook. Because individuals differ in their learning skills, the ActivEpi CD-ROM and the ActivEpi Companion...