What are different types of confounds?
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Confounds can be defined as uncontrolled variables. These variables make it difficult for researchers to determine whether the independent or uncontrolled variable were responsible for the observed effect. There are many different types of confounds. Some examples include the weather, time of day, or noise.
Example / Application
Example: [Confound Example]
Application: Let's say a professor wants to study whether more than 7 hours of sleep enhances student's final exam scores. This professor teaches a morning and a night class. He asks the students from both classes to indicate on a separate piece of paper how many hours they slept that night and asks them to turn this paper in with their final exam. This could measure the relationship between hours of sleep and the student's final exam scores. However, time of day may be a confound because one of his classes is in the morning and one is at night. The professor's students who are enrolled in his night class may have higher exam scores because they had more time to study and not because of the number of hours they slept. As you can see these variables make it difficult for researchers to determine whether the independent (hours of sleep) or uncontrolled variable (time of day the exam was taken) were responsible for the observed effect.