Loss of subjects is a serious threat to internal validity in an experimental study if:
A) the sample was too small to begin with
B) the loss is the same for all groups
C) more are lost from one group
D) losses are due to dislike of the researcher

Question

Quizplus · Accepted Answer

Loss of subjects from one group more than from others can introduce systematic differences between groups that are not due to the experimental manipulation, thereby threatening the internal validity of the study.

Loss of Subjects Is a Serious Threat to Internal Validity