Posttest-Only Control Group Design

The posttest-only control group design is a research design in which there are at least two [Page 1279]groups, one of which does not receive a treatment or intervention, and data are collected on the outcome measure after the treatment or intervention. The group that does not receive the treatment or intervention of interest is the control group. The general process for this design is that (a) two or more groups are formed; (b) the treatment or intervention is administered; (c) data are collected after the treatment or intervention has been administered, commonly using a behavioral, cognitive, or psychological assessment; and (d) the data are compared between groups to determine whether the treatment or intervention was effective. The goal of this design is often to make ...