Chapter Test
Sign In
What is the difference between an observational study and an experiment?
Observational study, see solution.
Let's begin by recalling the difference between an observational study and an experiment.
| Experiment | Observational Study |
|---|---|
| We randomly assign individuals either to a treatment group or a control group. | We select random samples for the groups being studied, and we do not control the individuals or their environment. |
Notice that in both methods we use a randomization. Now, let's take a look at the example research topic and try to determine which type of study would be better.
|
Market researchers want to know whether more men or women buy their product. |
Since we are interested in observing the real choices of customers, we should choose an observational study. We can observe the customers that buy our product and write down their gender.
Notice that using this method we are only able to recognize a correlation but not causality, because we do not control all of the conditions that can also affect the results.