The most important difference between an experiment and an observational study is the fact that; .<u>In an observational study the researcher has no control over the variables while an experiment involves application of treatments to a group and recording the effects.</u>
In an observational study researchers observe subjects and measure variables of interest without assigning treatments to the subjects. The treatment that each subject receives is determined beyond the control of the investigator.
In an experiment investigators apply treatments to experimental units (people, animals, plots of land, etc.) and then proceed to observe the effect of the treatments on the experimental units
