A type of non-experimental research, correlational research examines the relationship between variables. The purpose of this design is to establish if there’s a relationship between variables, and then to assess the strength and direction. Although correlational research can be useful in identifying patterns within data, it doesn’t establish cause-and effect relationships.
The nonexperimental type of quasi-experimental study aims at establishing cause-and-effect relationships among variables. A quasi-experimental research design is where the researcher manipulates one variable to observe its effect on another variable. However, unlike true experimental research, it does not randomize the assignment of participants to different groups. This is often used in situations where it’s not ethical or possible to assign participants randomly to groups.