What is the primary threat to internal validity that could confound the results of a regression discontinuity study?
A) maturation
B) selection-history
C) attrition
D) testing

Question

Quizplus · Accepted Answer

Selection-history is the primary threat to internal validity in a regression discontinuity design because it involves comparing groups based on a cutoff score, and any historical events that occur might differentially affect the groups based on their assignment, thus confounding the results.

What Is the Primary Threat to Internal Validity That Could