The Importance and Use of Normative Criteria to Manipulate Argument Quality

Argument quality plays an important theoretical and methodological role in persuasion research. Researchers frequently refrain from employing independent normative criteria to manipulate argument quality. Instead, they use pretests to qualify arguments that evoke predominantly favorable thoughts as strong and arguments that predominantly evoke unfavorable thoughts as weak. In this article, we analyze weak arguments as they have been used in actual studies. These weak arguments ranged from arguments referring to less favorable consequences compared to their strong counterparts, to consequences that are irrelevant to the participants, or even to undesirable consequences, thereby essentially functioning as counterarguments. We discuss the implications of this practice for our understanding of the persuasion process and our ability to provide evidence-based guidelines for message designers. We also provide guidelines on how to manipulate argument quality using normative criteria.