Physical Variables When an extraneous variable systematically changes across treatments,
A)the extraneous variable has the same value in the control and experimental conditions.
B)the extraneous variable has one value in the control condition and a different value in the experimental condition.
C)the independent variable has no effect on the dependent variable.
D)this presents a lower risk of confounding than when it changes randomly.

Question

Quizplus · Accepted Answer

When an extraneous variable systematically changes across treatments, it means that the extraneous variable is not randomly or evenly distributed between the control and experimental groups. This presents a higher risk of confounding because it becomes difficult to determine whether any observed differences in the dependent variable are due to the independent variable or the extraneous variable. Therefore, the extraneous variable should ideally have the same value in both groups in order to reduce the risk of confounding, but if it systematically changes across treatments, it is better for it to have a different value in the control and experimental conditions so that the effects of the independent variable can be accurately measured.

Physical Variables When an Extraneous Variable Systematically Changes Across Treatments