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Name: January 25, 2001 Score:

MATH 147

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Quiz 1

(1 pts.)

Problem 1. Circle T for a true statement, F for a false statement.

T F In an observational study, the effects of treatment may be confounded with the effects of factors that placed the subjects into the treatment or control groups in the first place.

(3 pts.)

Problem 2. Two teachers decide to conduct an experiment on the effectiveness of two teaching methods. It is decided that the forty students that are registered for the class will be divided into two groups. On the first day of class the two teachers meet with the students. The teachers alternate picking students from the group until each of them has a class of exactly twenty people. This is an example of

a. a historically controlled experiment.

b. a randomized controlled experiment.

c. a non-randomized controlled experiment.

d. an observational study.

e. Both a. and d.

(3 pts.)

Problem 3. Martha believes that people with brown eyes have higher IQ scores. To test this, she randomly selects 1000 people, takes note of their eye color, and then measures their IQ. This is an example of

a. a historically controlled experiment.

b. a randomized controlled experiment.

c. a non-randomized controlled experiment.

d. an observational study.

e. both a. and d.

(3 pts.)

Problem 4. Randomized controlled experiments

a. Tend to suffer from confounding factors.

b. Typically are more expensive and more difficult to perform than observational studies.

c. Are likely to be very inaccurate due to the randomness.

d. When it is ethical and possible to perform, are the best type of experiments.

e. both b. and d.