An experiment that uses the method of comparison to evaluate the effect of a treatment by comparing treated subjects with a control group, who do not receive the treatment.
C&P page: 247 Definition: An experiment designed to determine whether one thing causes another. It involves comparing an experimental group to which the suspected causal agent is applied, to a control group to which it is not, all other conditions being the same. Comment: Doesn't avoid bias or reversed order. Does it avoid 3rd factors? Intervening intelligence
an experiment where all variables are held constant except for the one under study