Comparative Change Design
Comparative Change Design allows for the measurement of change in relevant outcome factors (using a pre- and post-test) and provides for comparison of this change between a treatment group and a non-random comparison group. Because comparison and treatment groups are not randomly selected, alternate explanations due to prior differences between groups continue to be a threat.
US Environmental Protection Agency. (2007). Program Evaluation Glossary. Office of the Administrator/Office of Policy/Office of Strategic Environmental Management/Evaluation Support Division.