Loss of subjects is a threat to internal validity because:
A) it reduces the size of the sample
B) those "lost" may differ on the dependent variable from the remainder
C) it reduces the power of statistical tests of significance
D) it means that results of the study are less generalizable

Question

Quizplus · Accepted Answer

Loss of subjects can threaten internal validity if those who drop out differ in significant ways on the dependent variable from those who remain, potentially biasing the results.

Loss of Subjects Is a Threat to Internal Validity Because