Campbell's "reforms as experiments" article includes a description of an evaluation of a state police crackdown on speeding in Connecticut. There were 324 fatalities in the year before the crackdown and 284 in the year after. According to Campbell, the program was partially the cause of the drop, but ______ also occurred.
A)selection
B)maturation
C)instrumentation
D)regression to the mean

Question

Quizplus · Accepted Answer

Regression to the mean occurred because the initial high number of fatalities could have been an anomaly, and the numbers naturally moved closer to the average in the following year, contributing to the observed decrease.

Campbell's "Reforms as Experiments" Article Includes a Description of an Evaluation