Study designs: Part 2 - Descriptive studies.

One of the first steps in planning a research study is the choice of study design. The available study designs are divided broadly into two types - observational and interventional. Of the various observational study designs, the descriptive design is the simplest. It allows the researcher to study and describe the distribution of one or more variables, without regard to any causal or other hypotheses. This article discusses the subtypes of descriptive study design, and their strengths and limitations.