Imagine a Hypothetical Study Using a Nonequivalent Comparison Group Designed

Multiple Choice

Imagine a hypothetical study using a nonequivalent comparison group designed to assess the effectiveness of an anti-drug, "Just Say No," campaign. In this study students at school X receive a semester-long series of "Just Say No" lectures. Students at school Y across town do not receive the intervention. Unfortunately, during the semester a student at school Y died after an accidental drug overdose. This incident may have influenced drug use at school Y but not school X) and consequently make it impossible to interpret our research findings. Which of the following threats to internal validity is present in this study?

A) selection-instrumentation
B) selection-maturation
C) selection-history
D) selection-testing