Statistics Dictionary
To see a definition, select a term from the dropdown text box below. The statistics
dictionary will display the definition, plus links to related web pages.
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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.
