The whole emphasis of this book is to enable you to develop the skills needed to critically evaluate the research you read, so that this critical utilisation of research might inform the development of your clinical practice. This chapter is concerned with the relationship between the question the research sets out to answer, and the research design used to answer this question. This association between question and design is fundamental to the whole research process, because if an inappropriate design has been used to answer a research question, the quality of the research project will be fundamentally undermined.