In 1963, Donald Campbell and Julian Stanley initially designated the static group design, one of the three preexperimental designs. Preexperimental designs are best thought of as premature designs in that they have serious flaws and therefore should be avoided. The static group design is also called the posttest-only nonequivalent groups design. Consistent with this name, participants are nonrandomly assigned into two groups (experimental vs. comparison). Participants then take a posttest after receiving treatment. Importantly, there is no pretest, so it is impossible to ascertain whether any group differences are due to the experimental manipulation/treatment or preexisting differences.

Preexperimental designs such as the static group design are typically used to explore a relationship prior to a true experiment, although they are occasionally used in applied research after ...