Experiment which compares two or more interventionsÂ
Intervention is compared to control intervention (= no intervention or another type of intervention)
Participants for each intervention are randomly assigned
Common assignment to group: one intervention assigned to each individual
Cluster-randomization: assignment to defined groups of individuals (e. g. class, household)
Example:
Randomized-Controlled Trial: Treatment success for patient A with drug A in comparison to treatment success for patient B with already existing drug B
Cluster-Randomised-Controlled Trial: Prevalence of obesity in a community with a systematic physical activity program versus a community without any such program