Warning Effectiveness: What Do We Need to Know

The forensic area of practice for human factors engineers has brought into sharp focus the differences of opinion which exist regarding the effectiveness of warnings in bringing about safe behavior on the part of the user of a product. This paper addresses the major issues which the authors believe must be researched further to provide the definitive answers needed regarding the effectiveness of warnings in a variety of possible applications. A review of the literature will demonstrate that there are few studies of warning effectiveness per se, while there are many studies that address such issues as the need for warnings and presumed criteria for preparing effective warnings. It is suggested that further research is needed which addresses warning effectiveness in actual use situations, and in turn identifies the importance of such variables as stimulus energy level, information overload, risk perception, cost of compliance and the interaction of warnings, instructions and training.