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Principles of experiment design

AP.STATS:
VAR‑3 (EU)
,
VAR‑3.A.4 (EK)
,
VAR‑3.B (LO)
,
VAR‑3.B.1 (EK)
,
VAR‑3.C (LO)
,
VAR‑3.C.1 (EK)
,
VAR‑3.C.4 (EK)
A footwear company wants to test the effectiveness of its new insoles designed to prevent shin splints resulting from running. They hire a group of physical trainers and a statistician, who recruits 100 healthy adults between the ages of 18 and 24 to participate in a study.
The statistician randomly assigns 50 of the adults to follow a weekly running schedule with the new insoles and the other 50 to the same running schedule with the existing insoles the company already sells. After 10 weeks, the statistician records the number of runners from each group that have developed shin splints.
Problem 1
What is the primary purpose of having a group of 50 runners use the existing insoles?
Choose 1 answer:
Choose 1 answer:

problem 2
What is the primary purpose of randomly assigning the runners to use either the new or existing insoles?
Choose 1 answer:
Choose 1 answer:

problem 3
The researchers considered having one group use the new insoles and the other group use no insoles at all.
Why might this design lead to confounding?
Choose 1 answer:
Choose 1 answer:

Problem 4
Neither the participants nor the researchers collecting the data knew which group had the new insoles and which group had the existing insoles.
What is one reason for using this type of double-blind design?
Choose 1 answer:
Choose 1 answer:

Want to join the conversation?

  • stelly blue style avatar for user Elle
    for question 3: how would having people not wear insoles at all cause a placebo effect, at least compared to having them wear the normal insoles?
    (8 votes)
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    • starky sapling style avatar for user MrBentley.x
      The fact that the Treatment group has received something that the Control group hasn't might psychologically impact the Treatment group. The Treatment group might become more confident having received extra equipment. Compared to the Control group that didn't get to experience that little burst of excitement we all get from being introduced to something new.
      (5 votes)
  • blobby green style avatar for user sgopalan58
    >Problem 2: What is the primary purpose of randomly assigning the runners to use either the new or existing insoles?

    Roughly similar groups also reduce the confounding effect, right? Why should the answer not be B
    (3 votes)
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  • starky sapling style avatar for user Brian Pedregon
    Pedtrol was here
    (1 vote)
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  • male robot johnny style avatar for user Asiwome Agbleze
    Why should question 2 be A and not B?
    (1 vote)
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  • aqualine tree style avatar for user Maecie Rogahn
    My question got answered
    (1 vote)
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