This article examines constructs, propositions, and assumptions of the extended parallel process model (EPPM). Review of the EPPM literature reveals that its theoretical concepts are thoroughly developed, but the theory lacks consistency in operational definitions of some of its constructs. Out of the 12 propositions of the EPPM, a few have not been tested explicitly and not a single one received unequivocal empirical support. This article proposes alternative operationalization for some of the constructs and examines some assumptions of this theory, such as additive relationship between the constructs, the role of time and issue of thresholds, and disregard for the existing state of the audience. Finally, the role of the EPPM as a potential foundation for a general theory of negative emotional appeals is addressed.
Keywords behavioral theories, health communications, injury prevention/safety, measurement development, risk communicationScaring people to motivate them to change their behavior has been practiced for millennia. Systematic empirical investigation of fear appeals, on the other hand, is less than 60 years old (Dillard, 1994). Since the 1950s, several theories have been proposed to explain the processing and effects of fear appeal messages, and the extended parallel process model (EPPM; Witte, 1992) is one of the latest developments in this area. The EPPM integrates previous research on fear appeals in an attempt to answer a long-standing question of why fear appeals sometimes fail and sometimes succeed.The EPPM has many strong points that make it appealing to both scholars and practitioners of public communication campaigns. It was able to reconcile contradictory predictions and findings of its predecessors, it has an elegant and easy to understand structure, it is useful in guiding many decisions of public communication campaigns, and it served as a foundation for more than 50 empirical studies (Witte, Girma, & Girgre, 2003).But has the EPPM been supported to the extent it is assumed? A closer examination of the EPPM researchpresented in this article-demonstrates that contrary to the common beliefs, none of the EPPM's propositions received unequivocal support, some important assumptions remained unexamined, and the same constructs were measured in various ways in different studies making it difficult to pinpoint the explanation for disparate findings. The EPPM can still illuminate a great deal about responses to fear appeals if additional and more rigorous tests of the theory are undertaken with consideration for the diverse findings of past research.This article is organized in five sections. First, the EPPM is introduced through the brief history of its theoretical development. Second, the conceptual and operational definitions of the 11 constructs are presented. Third, research on each of the 12 propositions is summarized. Fourth, the assumptions underlying the EPPM are discussed. Finally, the last section provides recommendations for extending the model into the foundation for the coverin...