A Researcher Attempts to Evaluate the Impact of a Safety-Training

Multiple Choice

A researcher attempts to evaluate the impact of a safety-training program that is intended to increase the use of helmets by child bicyclists. About the same time that the training program takes place, the local news media runs a front-page story about a five-year old whose life was saved by wearing a helmet. This case most clearly illustrates the internal validity threat of:

A) history.
B) maturation.
C) testing.
D) statistical regression.