A sociologist studying freshmen carried out a survey, asking (among other questions) how often students went out per week, how many hours they studied per day, and how many hours they slept at night. The tables below provide the answers on the time slept and the time spent studying by whether or not students went out. When we examine the data, we find that students who studied more slept less, both among those who go out and among those who stay in the dorm. When we combine both groups of students, we find that those who studied more also slept more. This is an example of:
A)the Probability Paradox.
B)Andersen's Paradox.
C)the Gaussian Paradox.
D)Simpson's paradox.

Question

A sociologist studying freshmen carried out a survey, asking (among other questions) how often students went out per week, how many hours they studied per day, and how many hours they slept at night. The tables below provide the answers on the time slept and the time spent studying by whether or not students went out.  When we examine the data, we find that students who studied more slept less, both among those who go out and among those who stay in the dorm. When we combine both groups of students, we find that those who studied more also slept more. This is an example of:
A)the Probability Paradox. 
B)Andersen's Paradox. 
C)the Gaussian Paradox. 
D)Simpson's paradox.

Quizplus · Accepted Answer

This is an example of Simpson's paradox, which occurs when a trend appears in different groups of data but disappears or reverses when the groups are combined. In this case, the trend of higher studying leading to less sleep is present within each group (those who go out and those who stay in), but when we combine the groups, the trend reverses, and higher studying is associated with more sleep.

A Sociologist Studying Freshmen Carried Out a Survey, Asking (Among