In the social sciences, researchers often want to conduct studies in situations where they cannot control certain aspects of the study. For example, they might want to compare critical thinking skills for students taking an online class with those taking a face-to-face class. The independent variable is the type of class, and the researcher cannot manipulate it. One group enrolled in an online class by choice and another group enrolled in a face-to-face class by choice. Therefore there is no random selection. Additionally, the students are in class for nine weeks, and the researcher cannot control any critical thinking skills students might pick up during that time outside of class. These challenges cause threats to internal validity.It would be disappointing to give up on studying an important topic because the researcher cannot exert control over the variables in the study. Quasi-experimental research designs make it possible to conduct the study after all. A well-designed quasi-experimental study rules out some
This is the end of the preview.
access the rest of the document.