Answer:
observational study
Explanation:
In simple words, Since of moral considerations or practical constraints, an observational study makes generalizations from a subset to a community in which the predictor variables is not within the control of the researchers.
Observational research include the monitoring of subjects who have not been subjected to any forced changes in their circumstances, i.e., they have not been subjected to any treatment.
Observational investigations aim to explore the 'natural' condition of risk indicators illnesses, or consequences, despite the fact that participants' behavior may change while being observed.
