If participants in one treatment condition have characteristics that are different from the characteristics of participants in another treatment condition,then _______ may be threatened.
A)internal validity
B)external validity
C)reliability
D)accuracy

Question

Quizplus · Accepted Answer

Internal validity may be threatened because differences in participant characteristics can lead to confounding variables, affecting the causal relationship between the treatment and the outcome.

If Participants in One Treatment Condition Have Characteristics That Are