What is randomization used for in an experimental design?

Randomization plays a crucial role in experimental design by helping to avoid systematic relationships between two variables. This process involves randomly assigning participants to different groups, which minimizes bias and ensures that each group is comparable at the outset of the experiment. By doing so, researchers can ascertain that any observed effects or differences in the dependent variable are likely due to the manipulation of the independent variable rather than pre-existing differences among the participants.

When randomization is properly implemented, it helps distribute characteristics and potential confounding variables evenly across all groups. This means that if an effect is observed, it can be more confidently attributed to the experimental treatment rather than other external factors that might influence the outcome. Hence, this method is essential for establishing cause-and-effect relationships in experimental research.

The incorrect options focus on various aspects of experimental design but do not align with the primary purpose of randomization. For example, ensuring equal sample sizes across groups does not specifically require randomization; it can be achieved through other methods. Similarly, convenience selection of participants and the accurate measurement of the dependent variable are separate considerations that do not relate directly to the concept of randomization.