The Basics
In order to try and determine a correlation or causal relationship between an activity, exposure, microorganism, etc.. and a disease/condition, scientists must conduct a study. These studies can be very difficult to conduct due to ethical concerns, time constraints, money, patient compliance and a variety of other reasons. There are several different types of studies that researchers can choose from when trying to study a particular topic. The following TED-Ed activity will help you understand the terminology and various issues associated with these studies.
Not All Scientific Studies Are Created Equal