Question

A researcher studying consumer buying habits asks every 20th personentering Publix Supermarket how many times per week he or she goesshoppingObservational study or randomized experiment (circle one)?Explain:

Answer 1

Now, let us define both

An observational study is a study in which the researcher simply observes the subjects without interfering. That is, the researcher has no control over any treatments the subjects may be given or which groups the subjects may be separated into, etc.

While a randomized experiment involves randomly splitting a group into smaller groups: one group (the treatment group) receives the intervention, and one does not (the control group). The researcher selects the assignment mechanism, which is also random.

Now from the explanation of both above, we can see that the researcher randomly selected the people he interviewed or asked the question, splitting these people into every 20 persons and selecting one from every 20. He didn't just observed their habit, but randomized and intervened by asking them questions.

Hence the answer is randomized experiment