Randomization means
Randomization is a statistical procedure by which the study paicipants are allocated into groups usually called study and control groups; to receive or not receive an experimental preventive or therapeutic procedure, maneuver or intervention Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 90
Mixing of cases and controls
Selecting cases
Selecting controls
Vaccine and Erythromycin
Epidemiology