In Exercises 21–28, determine whether the study is an experiment or an observational study, and then identify a major problem with the study.

Drinking and Driving: A researcher for a consortium of insurance companies plans to test for the effects of drinking on driving ability by randomly selecting 1000 drivers and then randomly assigning them to two groups: One group of 500 will drive in New York City after no alcohol consumption, and the second group will drive in New York City after consuming three shots of Jim Beam bourbon whiskey.

A study is conducted with 1000 drivers to test the effect of alcohol consumption on driving ability. The entire sample is divided into two groups; one group of 500 drivers will drive without consuming alcohol, while the other half will drive after consuming three Jim Beam bourbon whiskey shots.

When a study is conducted toonly observe the outcomes of an effect without influencing any aspect of the population, it is referred to as anobservational study. It deals with only recording and collecting data and stating the observations made.

When a study is conducted totest the outcomes of an effect by systematically influencing a particular aspect of the population, it is referred to as anexperimental study. It deals with the comparison of a case group (with the treatment) and a control group (without the treatment).

The given study involves two groups of 500 drivers each to study the effect of alcohol drinking on driving skills. One group is asked to drive under the influence of three shots of bourbon whiskey, while the other group is made to drive without any influence of alcohol. Thus, it is an experimental study.

Before conducting any studies, it is essential to take care of certain factors like cost, time, and ethical issues involved. These issues prevent the researcher from conducting any study as it might lead to life-threatening damage.

Since the experiment needs subjects to drive under the influence of alcohol, it can be seriously injurious to their health. Therefore, due to the existence of critical ethical issues, the study is illegal and wrong.