When a change in the dependent variable could be due to how participants were picked or assigned to groups, __________ is a threat to internal validity.
A)history
B)maturation
C)regression to the mean
D)selection

Question

Quizplus · Accepted Answer

Selection refers to the possibility that the groups being compared are not equivalent to begin with due to how participants were chosen or assigned. This can introduce bias and make it difficult to determine if any changes in the dependent variable are truly due to the independent variable.

When a Change in the Dependent Variable Could Be Due