Which option is an example of a true experimental design type that involves random assignment and a control condition?

Which option is an example of a true experimental design type that involves random assignment and a control condition?

• A. Nonrandomized trial
• B. Quasi-experimental design
• C. RCT (between-subject): clinical treatment compared with control condition, where subjects randomly designed to groups
• D. Repeated Measures Design (within-subject)

Answer: (C)

Random assignment with a control group lets you infer causality by isolating the treatment effect. When participants are randomly allocated to receive the clinical treatment or to a control condition, the groups are, on average, equivalent at baseline. The control condition provides a counterfactual—what would have happened without the treatment—so differences in outcomes can be attributed to the treatment itself rather than to preexisting differences or other factors. This between-subject randomized controlled design is the classic true experimental type that embodies both random assignment and a control condition. Nonrandomized trials and quasi-experimental designs lack random assignment, which weakens causal claims because observed differences could be due to preexisting differences between groups. Repeated measures designs involve the same participants across conditions (within-subjects), which changes the design dynamics and isn’t the straightforward between-subject randomized comparison that includes a separate control group.

Random assignment with a control group lets you infer causality by isolating the treatment effect. When participants are randomly allocated to receive the clinical treatment or to a control condition, the groups are, on average, equivalent at baseline. The control condition provides a counterfactual—what would have happened without the treatment—so differences in outcomes can be attributed to the treatment itself rather than to preexisting differences or other factors. This between-subject randomized controlled design is the classic true experimental type that embodies both random assignment and a control condition.

Nonrandomized trials and quasi-experimental designs lack random assignment, which weakens causal claims because observed differences could be due to preexisting differences between groups. Repeated measures designs involve the same participants across conditions (within-subjects), which changes the design dynamics and isn’t the straightforward between-subject randomized comparison that includes a separate control group.