Collecting Data

 Practice Questions

More reading! Read this article about racial profiling of New Jersey drivers. Then answer these questions. Share your answers on the group discussion page.

1. A number of confounding factors were proposed in the article. What were they, and why are they confounding factors?

2. Do you agree that these confounders are valid?

3. Can you think of other confounders?

4. A claim is made that speeders (however defined) are more likely to be black than white. Does this necessarily mean that blacks are more likely than whites to be speeders? Explain.

(from Intro Stats by DeVeaux & Velleman)

Science News reported that depressed individuals cry no more often in response to sad situations than nondepressed people. Researchers studied 23 men and 48 women with major depression, and 9 men and 24 women with no depression. They showed the subjects a sad film about a boy whose father has died, noting whether or not the subjects cried. Women cried more than men, but there were no significant differences between the depressed and nondepressed groups.

5. Is this an observational study or an experiment? Why?

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