In a regression-discontinuity design the most likely validity threat is the:
A) random assignment
B) history effect
C) differential history effect
D) differential attrition

Question

Quizplus · Accepted Answer

Differential history effect is the most likely validity threat in a regression-discontinuity design because it can occur when the treatment and control groups are not equivalent on some important characteristic that is related to the outcome variable. This can lead to biased results, as the treatment effect may be overestimated or underestimated.

In a Regression-Discontinuity Design the Most Likely Validity Threat Is