Principles of experiment design
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 healthy adults between the ages of and to participate in a study.
The statistician randomly assigns of the adults to follow a weekly running schedule with the new insoles and the other to the same running schedule with the existing insoles the company already sells. After weeks, the statistician records the number of runners from each group that have developed shin splints.
What is the primary purpose of having a group of runners use the existing insoles?
What is the primary purpose of randomly assigning the runners to use either the new or existing insoles?
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?
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?
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?(9 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)
- Pedtrol was here(1 vote)
- what is confounding?(1 vote)
- 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)
- My question got answered(1 vote)