In a Nonequivalent Group Design, the Nonequivalence of the Groups

Multiple Choice

In a nonequivalent group design, the nonequivalence of the groups is sometimes demonstrated by a pretest. If a researcher is worried that the units of measurement on the scale are not equal throughout the scale, the researcher is worried about which threat to internal validity?

A) Maturation
B) History
C) Statistical regression
D) Instrumentation