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AP®︎/College Statistics
Course: AP®︎/College Statistics > Unit 6
Lesson 4: Introduction to experimental designPrinciples 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)
CCSS.Math: 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.
Want to join the conversation?
- 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?(10 votes)
- 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.(6 votes)
- >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)- Having 2 roughly similar groups doesn't guarantee that you might not have to deal with any confounding variables.(2 votes)
- Why should question 2 be A and not B?(1 vote)
- There is no reason that the experiment might limit replication. However, since the runners do not know which insoles they were given, it might create a placebo effect, where the runner thinks it will make running easier.(1 vote)
- In question 3 option 3 is also reasonably correct as we can say that by not providing insole to one group the study will become sort of observational as we can correlate whether having insole is reducing the shin splints. I agree that option 1 is most appropriate but again why option 3 shall be incorrect that I would like to know..(1 vote)
- My question got answered(1 vote)
- Pedtrol was here(0 votes)
- what is confounding?(0 votes)