Pre-experimental designs are so named because they follow basic experimental steps but fail to include a control group. In other words, a single group is often studied but no comparison between an equivalent non-treatment group is made.
Types of Pre-Experimental Design
One-shot case study design
One-group pretest-posttest design
Static-group comparison
One-shot case study design
A single group is studied at a single point in time after some treatment that is presumed to have caused change. The carefully studied single instance is compared to general expectations of what the case would have looked like had the treatment not occurred and to other events casually observed. No control or comparison group is employed.
One-group pretest-posttest design
A single case is observed at two time points, one before the treatment and one after the treatment. Changes in the outcome of interest are presumed to be the result of the intervention or treatment. No control or comparison group is employed.
Static-group comparison
A group that has experienced some treatment is compared with one that has not. Observed differences between the two groups are assumed to be a result of the treatment.
