An observational study is one of the most common types of studies that takes place in social sciences. It is commonly used in statistics, psychology, and epidemiology, where a smaller sample is used to draw white or conclusions about a larger population. In this type of study, the independent variable is not under the control of the researcher because of logistical constraints or ethical concerns. For example, an observational study might take place to take a closer look at the effects of a specific type of treatment on a group of subjects. Then, the subjects are compared to a larger control group outside the overall control of the investigator. An observational study is very different from a randomized control trial, where just about every parameter of the study is under the control of those running the experiment. An observational study is a way to take a look at a cross-section of the population and is typically faster than a randomized controlled trial; however, it is subject to being influenced by confounding variables, which can make the results of an observational study less trustworthy than those of a randomized control trial.