Why do the groups have to be equivalent at the start of an experiment?
A) If the groups are not equivalent at the start of an experiment, the experiment is contaminated by ethnocentrism.
B) If the groups are not equivalent at the start of an experiment, demand characteristics are more likely.
C) If the groups are not equivalent at the start of an experiment, it is impossible to conduct a replication.
D) If the groups are not equivalent at the start of an experiment, we cannot be certain that the IV caused any difference observed in the DV.

Question

Quizplus · Accepted Answer

Equivalent groups ensure that any observed differences in the dependent variable (DV) can be attributed to the manipulation of the independent variable (IV), rather than pre-existing differences.

Why Do the Groups Have to Be Equivalent at the Start