Comparison in Scientific Research

Which of the following topics would be best suited to comparative research?

• a.Studying the prevalence of alcoholism in the elderly.
• b.Identifying the orbits of newly discovered planets around stars.
• c.Determining the effect of caffeine on fetal development.
• d.Measuring the effects of various herbicides on common weeds.

One principal difference between comparative research and experimental research is that the comparative researcher does not subject a group to a treatment, but rather observes a group that either by choice or circumstance has been subject to a treatment.

• a.true
• b.false

The difference between a retrospective study and a prospective study is

• a.retrospective studies find negative effects, and prospective studies identify positive effects.
• b.retrospective studies look at historical events, while prospective studies look at events from the present forward.
• c.retrospective studies are less scientific than prospective studies.
• d.retrospective studies do not rely on data, while prospective studies do.

Comparative research studies are by definition less valid than experiments.

• a.true
• b.false

The comparative method can be used to answer questions about

• a.the side effects of a chemical or drug.
• b.the effects of man-made pollutants on the environment.
• c.the likelihood that a suspect's DNA matches that left at a crime scene.
• d.all of the choices are correct

Researchers conducting comparative studies use sample groups that are as similar to one another as possible. This is because they want to

• a.increase the number of individuals providing data.
• b.increase the number of treatments to use with the groups.
• c.reduce the number of controls affecting the results.
• d.reduce the number of variables affecting the results.

When Richard Doll and Austin Hill published their research in 1950, they stated that "smoking is a factor, and an important factor, in the production of carcinoma of the lung." Why couldn't they simply say that smoking causes lung cancer?

• a.There are other, uncontrollable variables that contribute to the disease.
• b.They did not have enough evidence to connect smoking with lung cancer.
• c.Research was being conducted on other causes of lung cancer at the time.
• d.They couldn't rule out the possibility that lung cancer caused people to smoke.