Sometimes performance differences could be attributed to an independent variable or to some basic difference in the composition of the two groups involved. When this occurs, there is said to be a threat due to
A)regression
B)maturation
C)attrition
D)selection

Question

Quizplus · Accepted Answer

Selection refers to differences in the composition of groups that can affect the outcome, making it unclear whether the independent variable or pre-existing differences caused the observed effects.

Sometimes Performance Differences Could Be Attributed to an Independent Variable