In epidemiology and statistics, an observational study draws inferences about the possible effect of a treatment on subjects, where the assignment of subjects into a treated group versus a control group is outside the control of the investigator. This is in contrast with experiments, such as randomized controlled trials, where each subject is randomly assigned to a treated group or a control group before the start of the treatment.
Read more about Observational Study: Reasons For Uncontrolled Experimentation, Degree of Usefulness and Reliability, Discussion
Famous quotes containing the word study:
“Let us, therefore, study the incidents of this [war], as philosophy to learn wisdom from, and none of them as wrongs to be revenged.”
—Abraham Lincoln (1809–1865)