CITI Research Methods Practice Test

Experimental design is the correct choice for establishing cause-and-effect relationships in research. This type of design allows researchers to manipulate one or more independent variables while controlling for other factors, which helps to assess their impact on dependent variables. By randomly assigning participants to different conditions or groups, researchers can determine whether changes in the independent variable directly lead to changes in the dependent variable. This method minimizes the influence of extraneous variables and helps establish a clear causal link.

In contrast, case study design focuses on an in-depth analysis of a single case or a small number of cases without the manipulation of variables, making it challenging to infer cause-and-effect relationships. Survey design typically involves collecting self-reported data from individuals, which can be effective for understanding correlations and trends but does not provide the necessary control to deduce causality. Observational design allows researchers to observe subjects in their natural environment without intervention, which limits their ability to isolate factors that may influence outcomes and, therefore, does not adequately support causal inferences.