Answer: In observational study observer has no control on the variables but in an experiment experimenter has control over the independent variable to record the change on the dependent variable.
Step-by-step explanation:
In statistics , an observational study is a study in which a researcher just observe effects on subjects in a certain manner without interfering them.
On the other hand an experiment is a process which is done by experimenter to demonstrate a known fact or create a discovery by applying some methods to the variables .
The basic difference between an observational study and an experiment is<em> in observational study observer has no control on the variables but in an experiment experimenter has control over the independent variable to record the change on the dependent variable.</em>
