Quasi-Experimental Designs
In Study 1, the independent variable is the gender, whereas the dependent variable is the score on the mathematics section since it’s what we’re measuring. Also, the gender is the participant variable in this case. What’s problematic about this study is that the basis of their scores may be dependent on other variables other than gender. For instance, the quality of education or tutoring outside of the home may be influential factors on the scores. Also, there may be a threat to internal validity by way of regression to the mean. A student may be a high performer the first time around when the scores were recorded, but a slightly lower performer next. Since participant-variable designs are used to compare groups (Stangor, 2013), this study could possibly be a single-group design. However, it would not be possible to infer the causes between genders. Also, there is no control-group much like there isn’t one in a participant variable design.
In Study 2, the independent variable is socioeconomic status and the dependent variable would be the grades. An issue with this study is that other factors may affect the results, such as quality of tutoring and environment. This may have a different impact on the students. A single-group before-after design could also be utilized for this study. In a comparison-group before-after design, the focus is on having two more groups, one of which is a control group (Stangor, 2013). A single-group before-after design does not have a control group (Stangor, 2013). In this case, there would be no way to determine the effects of the tutoring with regards to SES.