Statistics Dictionary

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Experimental Design

The term experimental design refers to a plan for assigning subjects to treatment conditions. A good experimental design serves three purposes.

  • Causation. It allows the experimenter to make causal inferences about the relationship between independent variables and a dependent variable .

  • Control. It allows the experimenter to rule out alternative explanations due to the confounding effects of extraneous variables (i.e., variables other than the independent variables).

  • Variability. It reduces variability within treatment conditions, which makes it easier to detect differences in treatment outcomes.
See also:   Experimental Design