Conceptual, Empirical, and Practical Issues in Developing Valid Measures of Public Communication Campaign Exposure

The ability to validly measure campaign exposure is central to claims of public communication campaign effectiveness. Surprisingly, scholars have paid remarkably little attention to questions about the validity of various ways to measure campaign exposure. This paper begins to address this gap by outlining conceptual, empirical, and practical issues in developing valid measures of campaign exposure. First, I offer a brief definition of measurement validity and describe a variety of measurement options utilized in recent, large–scale health communication campaign evaluations. Next, I outline conceptual and empirical assumptions behind these various measurement strategies. I continue with a review of research that has applied validation criteria to specific measures of campaign exposure. I conclude by offering a series of guidelines for exposure measurement and validation practices based on the evidence to date, which I caveat by describing tensions and emergent issues that researchers will need to consider in future work.