1.A weight loss program provides three follow-up methods to choose from for individuals who went through the program and reached their desired weight: monthly in-person meeting, monthly on-line meeting, and monthly newsletter by mail. In order to assess the effectiveness of the three follow-up methods, the program selects a random sample of 291 individuals who went through the program and reached their desired weight and classifies them according to the follow-up method that they sign-up for. A year later the study finds that 30% of those who chose to sign up for the in-person follow-up method regained more than 5 pounds, 50% of those who chose to sign-up for the online method regained more than 5 pounds and 70% of those who chose to sign-up for the newsletter method regained more than 5 pounds.

Which of the following is the correct design of this study?

A randomized experiment

A randomized response study

A blind observational study

An observational study

A randomized observational study

2.In this case, can we conclude that any association that is found in the sample was due to causation? In other words, can we conclude that the follow-up method is the cause for whether or not the sampled individuals regained more than five pounds within a year?

Yes, since the individuals were randomly assigned to one of the the three follow-up methods

Yes, because of the relatively large sample size (n=291)

n=291 .

No, because association never implies causation

No, since the sample was random

No, since the individuals chose themselves which follow-up method to sign-up for.

3. 'Smart drinks' are beverages containing vitamins and amino acids, which are marketed as helpful to mental performance. To investigate the claimed effect of a particular 'smart drink' for the general adult population, a health researcher obtains 250 adults who volunteer for a beverage-and-memory study. Each of the subjects is then randomly assigned to get one beverage from among two possible: Either the 'smart drink' or else a 'fake smart drink' - a drink that looks and tastes the same as the 'smart drink', but does not contain any vitamins or amino acids). The subjects did not know which of the two beverages they were assigned to drink. After drinking, each subject is told to memorize a list of words; the subjects are then tested on how many words they can correctly recall. The number of correctly-recalled words is recorded for each subject.

Which of the following best describes the design of this study?

A blind experiment

A blind observational study

A blind survey

A survey

An experiment

An observational study

4. If the number of words recalled is really significantly higher on average in the 'smart drink' group, can we reasonably conclude that the improved recall of those in the 'smart drink' group was actually caused by the smart drink?

Yes, because this study has a control group.

Yes, since the individuals were randomly assigned to drink either the 'smart drink' or the 'fake smart drink'.

Yes, because of the relatively large sample size (n=250)

n=250 .

No, because the individuals were randomly assigned to drink either the 'smart drink' or the 'fake smart drink'.

No, since the adults volunteered to participate in the study

No, because the subjects didn't know whether they were drinking the 'smart drink' or the 'fake smart drink'.

5. A study explored the relationship between drinking diet soda and the risk of stroke. The researchers followed a group of individuals who are 'diet soda drinkers' and a group of individuals who are not diet soda drinkers and found a higher rate of stroke among those who are diet soda drinkers. After the researchers collected more data, they discovered that the weight of the individuals was significantly higher, on average, in the diet soda drinkers group.

Which of the following is true?

Weight is the explanatory variable

Weight is the response variable

Weight is a lurking variable

None of the above

6. "Fill in the blank" question: select the correct answer.

A study was conducted to explore the effect of handwriting style (cursive or block letters) on the score of an SAT essay. An identical essay was shown to a random sample of 120 SAT essay graders. The graders were randomly assigned to grade a cursive version of the essay or a version with printed block letters. The average score of the essay with the cursive style was higher than the average score of the essay with the printed block letters.

Complete the the following sentence:

This (observational study, experiment) is (not blind, blind) and (does not have, has) a control group

7. When designing and writing questions for a survey, which of the following are issues that you need to pay attention to?

Wording of questions

Order of questions

Sensitive questions

All of the above

8. Which of the following would be the best question to include in a poll in order to assess the opinions of U.S. adults about legalizing marijuana?

Which of the following best describes your view about legalizing the use of marijuana?

1) Strongly favor legalizing the use of marijuana

Favor legalizing the use of marijuana

Oppose legalizing the use of marijuana

Strongly oppose legalizing the use of marijuana

Not sure

2) Given the research that has shown that those who use marijuana heavily prior to age 25 are more likely than nonusers to experience a drop in IQ, which of the following best describes your view about legalizing marijuana?

Strongly favor legalizing the use of marijuana

Favor legalizing the use of marijuana

Oppose legalizing the use of marijuana

Strongly oppose legalizing the use of marijuana

Not sure

3) Given the medical benefits of marijuana and the research that has shown that marijuana is less addictive than nicotine, which of the following best describes your view about legalizing marijuana?

Strongly favor legalizing the use of marijuana

Favor legalizing the use of marijuana

Oppose legalizing the use of marijuana

Strongly oppose legalizing the use of marijuana