One group, known as the experimental group, receives the intervention under consideration, while the other, known as the control group, receives an alternative therapy, such as a placebo or no intervention. The goal is to determine which type of treatment is more effective. There are two types of groups in a randomized controlled trial: equal numbers in each group and not necessarily equal numbers in each group. For example, one researcher might assign 50% to receive the new treatment and 50% to receive the standard treatment. Another researcher might assign all those eligible for the study to receive the new treatment or the standard treatment without knowing which one they had been assigned to receive. In this case, there would be more participants in the standard treatment group than in the new treatment group. Equal numbers in each group ensures that both groups are equivalent with respect to important factors such as age, gender, socioeconomic status, disease severity, and so on. This is necessary because if one group is favored by some factor, it could influence the results. Not necessarily equal numbers in each group allows researchers to compare treatments that may not be offered to everyone. For example, if money were no object and a cure was found for cancer, then this study design would allow researchers to know which treatment was more effective without having to perform the study on every patient.