During the intervention, Manu got married and his test scores showed significant improvement. The most likely threat to internal validity this poses is:
A) History
B) Regression
C) Instrumentation
D) None of the above

Question

Quizplus · Accepted Answer

History refers to specific events occurring between the first and second measurements in addition to the experimental variables. Manu getting married is an external event that could have influenced his test scores, posing a threat to the study's internal validity by introducing variables not accounted for by the experimental design.

During the Intervention, Manu Got Married and His Test Scores