Reflect on the Are You Equipped Now at the end of the chapter.The article indicated that about 11% of the participants had already received acupuncture in the year before the treatment.This fact is associated with which of the following threats to internal validity?
A)selection
B)maturation
C)regression to the mean
D)attrition

Question

Quizplus · Accepted Answer

The fact that 11% of the participants had already received acupuncture before the treatment suggests that there may be a selection bias in the sample. People who have already received acupuncture may have different characteristics than those who have not, which could affect the internal validity of the study.

Reflect on the Are You Equipped Now at the End