Research design is the process of linking together all the elements of your research project. None of the elements can be taken in isolation, but must all come together to maximize your ability to speak to your theory (and research question) while maximizing internal and external validity within the constraints of your time and budget. The planning process is not straightforward and there are times that you will feel you are taking a step backward0-. That kind of progress’’ is normal.
Additionally, there is no single right way to design a piece of research to address your research problem. Different scholars, for a variety of reasons, would end up with quite different designs for the same research problem. Design includes trade-offs, e.g., internal vs. external validity, and compromises based on time, resources, and opportunities. Knowing the subject matter – both previous research and the subject itself – helps the researcher understand where a contribution can be made and when opportunities present themselves.
The symbol R means there is a random assignment to the group. X symbolizes exposure to experimental treatment. O is an observation or measurement.↩