Which of the following is not a threat to internal validity?
A) history
B) maturation
C) attrition
D) efficiency

Question

Quizplus · Accepted Answer

Efficiency is not a threat to internal validity. The other options are all potential threats. 
- History refers to external events that occur during the study and could impact the results. 
- Maturation refers to participants naturally changing over time (e.g. becoming older, more experienced) and this could impact the results. 
- Attrition refers to participants dropping out of the study, which could create bias in the results if those who drop out are different from those who remain in the study.

Which of the Following Is Not a Threat to Internal