Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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We say that the design of a study is biased if
which of the following is true?
a. | A racial or sexual preference is
suspected | b. | Random placebos have been
used | c. | Certain outcomes are systematically
favored | d. | The correlation is greater than 1 or less than
–1 | e. | None of the
above. |
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2.
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Control groups are used in experiments in order to
. . .
a. | Control the effects of lurking
variables | b. | Control the subjects of a study so as to insure all
participate equally | c. | Guarantee that
someone other than the investigators, who have a vested interest in the outcome, control how the
experiment is conducted | d. | Achieve a proper
and uniform level of randomization | e. | None of the
above. |
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3.
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A chemical engineer is designing the production
process for a new product. The chemical reaction that produces the product may have a higher or
lower yield depending on the temperature and the stirring rate in the vessel in which the reaction
takes place. The engineer decides to investigate the effects of combinations of two
temperatures (50°C and 60°C) and three stirring rates (60 rpm, 90 rpm, and 120 rpm) on the
yield of the process. Ten batches of feedstock will be processed at each combination of
temperature and stirring rate.
How many treatments are there in this
experiment?
a. | 2 | b. | 3 | c. | 5 | d. | 6 | e. | None of the
above |
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4.
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We wish to investigate if a new medicine is
effective in reducing the length and severity of the flu. We take the next 20 patients that come to
the walk-in clinic complaining of flu and, after a medical exam to verify that the patients do have
the flu, we give them the new medicine and tell them about the new drug we are giving them. One week
later, the patients are contacted and 15 patients state the new remedy was helpful in reducing the
severity and length of the illness. Which of the following is not
correct?
a. | This is a poor experiment because there is no control
group. We do not know how many would feel better in a week without
treatment. | b. | This is a poor
experiment because it is not double-blinded. The patients may feel relief because they thought the
drug should work. | c. | This is a poor
experiment because a convenience sample was selected. Patients who come to the walk-in clinic may
have more severe flu than people who do not. | d. | This is a poor
experiment because we didn't give the remedy to people without the flu to assess its effect in a
control group. | e. | This is a poor
experiment because the sample size is likely to be too small to detect anything but a gross
improvement in measuring the proportion of people reporting an
improvement. |
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