Guideline 1: Identify the goal, type, the population.
1) For the study described below, identify the population.
1500 American women working for large companies were polled to determine the percentage that felt that
women were under represented in management positions in their company.
A) All American women
B) The percentage of American women working for large companies who feel that women are under
represented in management positions in their company.
C) All American women working for large companies
D) The 1500 women polled
2) If the above study only minority women were selected, what this be an adequate population?
3) What type of study would best meet your goal---observational, experiment or case control?
4) You want to know the percentage of college seniors who regret their choice of major.
What would be an adequate population to study?
In order to answer the given question, which of the following types of study would be the most appropriate: an
experiment without blinding, an experiment with single blinding, an experiment with double blinding, an observational
study, or a case-control study?
5) Does smoking elevate blood pressure?
A) Experiment without blinding
B) Case-control study
C) Observational study
D) Experiment with single blinding
E) Experiment with double blinding
6) Do people prefer your new ice cream flavor to the old favorite of "death by chocolate"?
A) Observational study
B) Experiment with double blinding
C) Case-control study
D) Experiment without blinding
E) Experiment with single blinding
Guideline 2: Consider the source.
Would you believe this study?
The group conducting the study.
7) A pharmaceutical company conducted a study to test the effectiveness of its new anti-depression medication.
500 adults suffering from depression were selected at random and were randomly assigned to either a
treatment group or a placebo group. The experiment was double blind. The results were analyzed by the
company.
8) Should you believe this study?
A study conducted by Republicans is designed to assess a new Democratic tax cut plan.
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Guideline 3: Look for bias in the sample.
Selection bias occurs whenever the sample in selected in such a way the sample in unrepresentative of the population
Partcipation bias occurs whenever participation in the sample is voluntary.
Determine whether the study involves selection bias, participation bias, both selection bias and participation bias, or
neither.
9) You are interested in the degree of satisfaction amongst customers at your video store. For one week, you hand
a customer satisfaction questionnaire to every customer who comes into the store and ask them to fill it out and
place it in a box after they check out.
A) Participation Bias
B) No Bias
C) Selection Bias
D) Participation Bias and Selection Bias
10) You are interested in the percentage of people in your city who favor tax cuts. You interview every twentieth
person as they leave the church in your neighborhood.
A) Participation bias and selection bias
B) Participation bias
C) No bias
D) Selection bias
11) As voters left various polls across the city, every tenth voter at each polling place was asked who they had
chosen to be the next mayor.
A) Selection Bias
B) Participation Bias
C) No Bias
D) Participation Bias and Selection Bias
Guideline 4: Look for difficulty in defining the quantity of interest.
The quantitiy of interest is the parameter you are trying to measure.
12) What is the quantity of interest in the following and please define it?
A researcher randomly selected 500 college students and asked "How many IQ points would you sacrifice to
become better looking?". The following conclusion was published in the student newspaper "Students would
sacrifice 18 IQ points to be better looking."
Would this study present a problem? What is the variable of interest?
13) A researcher was interested in the exercise habits of the residents of the village of Pine Heights. She interviewed
every 10th person who left the post office until she had interviewed 100 people. Each of the people interviewed
was asked to rate their exercise level according to the following scheme "(1) very little, (2) some, (3) moderate,
(4) a lot, (5) extensive". The researcher reported that, on average, the residents of Pine Heights exercise
moderately.
14) Which of the following quantities of interest would be the most difficult to define?
A) The levels of lead in various brands of paint
B) The least expensive brand of paint
C) The paint with the best looking finish
D) How water resistant a brand of paint is
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Guideline 5: Watch for confounding variables---variables that are not intended to be part of the study.
15) A medical researcher randomly selects 500 Japanese people and 500 Americans. She questions the 1000 people.
She finds that the Americans work longer hours on average and also that the Americans have a higher rate of
heart disease. She concludes that working longer hours is associated with a higher incidence of heart disease.
Are there other factors that might have made a difference? If so they are called confounding variables.
16) An educational researcher wishes to compare the effectiveness of two different math textbooks. She has the
tenth graders at one school use the first book for one year and the tenth graders at another school use the
second textbook for one year. At the end of the year, she gives the same math test to both classes and compares
the results. Are there other factors that could have made the difference? If so they are called confounding
variables.
Guideline 6: If a survey is involved consider its setting and wording.
17) A health researcher randomly selected 500 high school students from the city of Oak Grove. In a private
interview the researcher asked the students whether they had ever used drugs. She concluded that only 8% of
the high school students of Oak Grove have ever used drugs. Would the setting make a difference?
Choose the best wording for the question in the study.
18) A recent magazine article determined that the Gemini is the most popular car on the road. A TV journalist
decided to check the accuracy of the article by conducting a survey. Which of the following survey questions
will give the journalist the most accurate results?
A) Do you agree that the Gemini is the most popular car on the road?
B) What kind of car do you recall seeing most often on the highway?
C) What kind of car do you drive?
D) What do you think is the most popular car on the road?
19) If you wanted to determine if your customers are satisfied with the selection in your store, which of the
following survey questions would give you the most accurate results?
A) Is there anything you would have purchased if our stock was not without it?
B) Are you satisfied with the selection at this store?
C) Do you agree that our selection is better than our competitor?
D) Is our selection as good as the selection of our competitor?
20) Guidline 8: Stand back and consider---What do the conclusions mean to you?
You like coffee and maxwell house does a study on how drinking coffee keeps you alert.
You like to exercise and 24 hour fitness does a study on how exercise daily prolongs your life.
You like wine and Nappa Valley does a study on how a glass of wine daily keeps you young.
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