Stanley Campbell's research design primarily utilizes which model?

Stanley Campbell's research design is strongly associated with the pre-test/post-test model. This model is commonly used in experimental research to assess the effects of an intervention by measuring participants before (pre-test) and after (post-test) the intervention is applied. This method allows researchers to evaluate the impact of the intervention by comparing outcomes, thus providing a clearer understanding of any changes that occurred as a result of the treatment.

By implementing this design, researchers can control for variables that might influence the results, making it easier to isolate the effect of the intervention being studied. This approach is particularly effective in fields such as education and healthcare, where measuring the impact of specific programs or treatments can directly inform practice and policy decisions.

The other models listed, such as comparative analysis, time series, and control group models, while valuable in their own right, do not encompass Campbell's primary focus on measuring outcomes through a direct before-and-after comparison. Therefore, the pre-test/post-test model is recognized as a hallmark of Campbell's contributions to research design.