Changes in Definitions and Operationalizations in Advertising Research—Justified or Not?

Abstract Many advertising constructs vary considerably in how they are defined and operationalized—variations which result from changes in definitions and operationalizations over time and between studies. These changes undermine the comparability of empirical insights, challenge the integration of insights into an existing body of knowledge, and thereby impede knowledge development in advertising research. This negative effect is why it is crucial to know whether and when changes are needed and justified. In this article, we address definition and operationalization change from a theoretical perspective, identify factors driving changes in definitions and operationalizations, and outline when changes are justified. We then offer recommendations for how to avoid unjustified changes.