ABSTRACT
The key difference is their scope. In each, information (data) is collected from individual subjects, but in medical research the aim is to be able to make some general statements about a wider set of subjects, and the researchers are not usually specifically interested in the particular subjects that have been studied. The subjects who are studied act as a proxy for the total group of interest. Researchers thus use information from a sample of individuals to make some inference about the wider population of like individuals, since researchers can never study, for example, all asthmatic patients.
