ABSTRACT
The chosen research design frames the study, addresses the research question, and limits any conclusions that can be made. Chapter 3 described the main types of research design ranging from qualitative designs with interviews and focus groups to experiments and randomised control trials. This chapter will highlight the problems arising from the different research designs with a focus on researcher bias, reverse causality, the third factor problem, and ecological validity. It will also describe how these problems can be solved but how many of these solutions introduce their own problems. These different problems are illustrated with a worked example from a research study.
