Chapter 13 Card #1
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Coffee stations in offices often just ( sk users to leave money in a tray to pay for their coffee, but many people cheat.
Researchers at Newcastle University replaced the picture of flowers on the wall behind the coffee station with a picture
of staring eyes. They found that the aver age contribution
increased significantly
above the well-established
standards
when people felt they were being watched, even though the eyes were patently not real. (NY Times, 12/10/06)
a.
Was this a survey, an observationai
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study, or an experiment?
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Card # 2
A runnil';j shoe manufacturer
wants to test the effect of its new -?printing shoe on 100-meter dash times. The company
sponsors 5 athletes who are running the 100 meter dash in the 2004 Summer Olympic Games. To test the shoe, it has all
5 runners run the 100 meter dash with a competitor's
shoe and then again with their new shoe. The company uses the
difference in times as the response variable.
a.
Suggest some improvements
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Card #3
Athletes who had suffered hamstring injuries were randomly assigned to one of two exercise programs. Those who
engaged in static stretching returned to sports activity in a mean of 15.2 days faster than those assigned to a program of
exercises (Journal of Orthopaedic & Sports Physical Therapy 34 [March 2004]:3)
agility and trunk stabilization
a.
Why was it important
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to assign the athletes to the two different treatment
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groups randomly?
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in a special exercise program. Explain
the advantage of including such a group.
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Card #4
An experiment
that showed that subjects fed the DASJ:Idiet were able to lower their blood pressure by an average of 6.7
points compared to a group fed a "control
a.
Why were the subject randomly assigned to the diets instead of letting people pick what they wanted to eat?
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would you want to know in order to decide whether an average reduction in blood
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Card #5
A study published in the New England journal of Medicine (Aug 2001) suggests that it is dangerous to enter a hospital on
a weekend. During a 10 year period, researchers tracked over 4 million emergency admissions to hospitals in Ontario,
Canada. Their findings revealed that patients admitted
on weekends had a much higher risk of death than those who
went on weekdays.
a.
The researchers said the difference in death rates was "statistically
significant."
Explain in this context what that
means .
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If you think you are quite ill on a Saturday, should you wait until Monday to seek medical help? Explain.
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Card #6
A research doctor has discovered a new ointment
the treatment
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that she believes will be more effective than the current medication
hired as a consultant to help design a completely
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Describe and diagram how you will conduct this experiment.
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have volunteered to participate in the initial trials of this
of shingles (a painful skin rash). Eight patients
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Using the random numbers listed below, show which patients are assigned to each treatment. Explain your
randomization procedure clearly.
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