An urban community clinic wants to try a new method of getting drug addicts to kick their addiction. They advertise for participants in their lobby, and allow volunteers to choose to participate either in the treatment or control group. Three months later, they find that 65% of the volunteers are off drugs. This example illustrates the possibility of __________ as a plausible rival hypothesis.
A) history
B) maturation
C) regression artifact
D) selection

Question

An urban community clinic wants to try a new method of getting drug addicts to kick their addiction. They advertise for participants in their lobby, and allow volunteers to choose to participate either in the treatment or control group. Three months later, they find that 65% of the volunteers are off drugs. This example illustrates the possibility of   __________ as a plausible rival hypothesis.
A) history
B) maturation
C) regression artifact
D) selection

Quizplus · Accepted Answer

The example illustrates the possibility of "selection" as a plausible rival hypothesis because participants were allowed to choose whether they wanted to be in the treatment or control group. This self-selection could mean that those who chose the treatment group were already more motivated or ready to quit, skewing the results.

An Urban Community Clinic Wants to Try a New Method