3.01

Q1. Teenagers signed up to be subjects in a psychology experiment. When they arrive, they are told that interviews are running late, and they are left waiting outside. The experimenters have placed a sign next to the entry door that says, "Do not open the door under any circumstances." Some subjects are outside alone and others are in pairs; these are the treatments being compared. Will the subject open the door? The teenagers agreed to take part in an unspecified experiment, and the true nature of the experiment is explained to them afterward. Does this meet the requirement of informed consent? Explain.

ANSWER CHOICES

A.No, because they had to wait for the interviews

B.No, because they did not know the nature of the experiment before participating

C.Yes, because they agreed to participate in an experiment

D.Yes, because they are not forced to open the door

E. Unable to determine whether subjects consented to experiment

Q2. An observational study found that the amount of time a child spends learning a second language is associated with standardized testing performance. The correlation coefficient was found to be r = 0.94. A conclusion was made that the more time a child spends learning a second language, the better the child performs on standardized tests. Why is such a conclusion not correct?

ANSWER CHOICES

A. The sample was not representative of the population.

B. The correlation value should be negative for such a conclusion.

C. The correlation value should equal 0 for such a conclusion.

D. Causation cannot be determined from an observational study.

E. The correlation value implies that less than 90% of the variability in standardized testing performance can be explained by learning a second language.

Q3. A study revealed a strong, linear, positive association between the amount of shampoo used and the length of hair. Another study revealed a strong, linear, positive association between amount of conditioner used and the length of hair. When the data were combined, the association became negative. What is this an example of?

ANSWER CHOICES

A. Observational study

B. Experimental study

C. Simpson's Paradox

D. Cause-and-effect relationship

E. Error by the statistician

Q4. An education company representative speaking on a local radio station has advocated that middle school students download a particular app on their phone. The individual cited a study of 1,000 randomly selected middle school seventh- and eighth-grade students that reported that students who downloaded the app on their phones, on average, scored 30 points higher on the Algebra I end-of-course exam than those who did not download the app. Which of the following statements is correct?

ANSWER CHOICES

A. There seems to be a relationship between the app and obtaining a higher score on the Algebra I exam.

B. Because downloading the app seems to improve standardized test scores for middle school students, the app should be effective for high school students.

C. Downloading the app will cause a student to score higher on an AP Statistics exam.

D. The study was an experiment rather than an observational study.

E. The sample size of the study was too low to determine a result.