Epidemiology is the study of the distribution and determinants of health-related events in human populations and the application of this study to control health problems. This book is a student's guide to basic analytic study designs in epidemiology, such as the prospective cohort design. It is meant to serve as a supplemental resource for those who are taking formal courses in disciplines such as epidemiology, health statistics, and population health science. It can also serve as an on-the-job reference manual for practitioners. To enhance understanding, information is structured in the forms of outlines, definitions, tables, formulas, and quizzes. The most powerful information structure is the concept map, which is a diagram showing how terms and ideas interconnect.