Quasi-experimental designs were developed to deal with the messy world of field research, where it is not always practical, ethical, or even possible to randomly assign persons to experimental and control groups.
The little orange ball beside each design is "clickable" and will take you to a discussion of that design.
Some examples of quasi-experimental designs are:
Time Series Design
Control Group Time Series Design
Equivalent Time Samples Design
Equivalent Materials Design
Non-equivalent Control Group Design
Separate Sample Pretest-Posttest Design
Separate Sample Pretest-Posttest Control Group Design
Multiple Time Series Design
Recurrent Institutional Cycle Design
Return to the research flowchart.