A state passes a law requiring mandatory seatbelt use and claims it has reduced traffic fatalities. At the same time that the seatbelt law was changed, speed limits were also reduced from 70 MPH to 55 MPH by the federal government. Traffic fatalities decreased during the first year of the seatbelt law. The change in the speed limits represents what kind of threat to internal validity?
A) Maturation effect
B) Instrumentation effect
C) Testing effect
D) History effect

Question

Quizplus · Accepted Answer

The change in speed limits is a history effect because it is an external event that occurred simultaneously with the seatbelt law, potentially influencing the decrease in traffic fatalities.

A State Passes a Law Requiring Mandatory Seatbelt Use and Claims