Which threat to internal validity is related to an uneven loss of subjects from an investigation?
A) Statistical regression
B) Differential subject selection
C) Experimental mortality
D) Local history

Question

Quizplus · Accepted Answer

Experimental mortality, also known as attrition, occurs when participants drop out of a study before it is complete. If there is an uneven loss between the experimental and control groups, it can threaten the internal validity of the study as the groups may no longer be equivalent.

Which Threat to Internal Validity Is Related to an Uneven