Types of Studies

This lecture series discusses the difference between observational studies and experiments and the conclusions you can draw from each.

1. The researcher used an observational study.

The study is not appropriate for the question because it doesn't allow the researcher to show that marriage causes careful driving.

2. The scientists used an experiment.

We can validly conclude that the results suggest that adopting an exercise regime may increase sleep duration among overweight men.

3. Vishal used an observational study.

The study is not appropriate for the question because he only interviewed people who agreed to it.

4. The researchers used an experiment.

We can validly conclude that the result suggests that meditation can reduce work stress.