Researchers use single factor experimental designs to try to study causal relationships. For example, if researchers want to know if an exercise intervention reduces depression, they might randomly assign some participants to receive the exercise intervention and others to not. They could collect baseline and post-intervention data and compare the two groups. If the treatment group showed a significantly greater reduction of depression than the control group, the researchers would conclude that the exercise intervention reduced depression. Think of a topic of interest. Create a research question and hypothesis. Summarize how you would construct a study to test your hypothesis. Discuss if you want to study this using a between subjects or within subjects design? Explain. Discuss if you want to use random assignment or random sampling. Explain why or why not.