Some clinicians may feel dissociated from, and intimidated by the ever-increasing emphasis on research. However, with an understanding of some of the basic principles and key terms, research can feel less daunting. It is the aim of this article, the second in a series of three focusing on understanding research, to introduce clinicians to the different approaches to research, to improve understanding of what the approaches mean, and to highlight when a particular approach may be appropriate. Furthermore, the article will provide an explanation of some of the common terms used within clinical research. This should aid the clinician in applying good, simple, scientific principles to evaluating clinical research evidence.