This book summarizes research findings concerning various types of warnings in the last thirty years. It is divided into six sections with comprehensive coverage on different means of warnings, ways of evaluating the effectiveness of warnings, and selection of warning labels in different modalities. The book focuses primarily on the attention getting or alerting component of warning such as color, signal words, and shapes of background of warning labels, acoustic structure of nonverbal auditory displays, and the pitch and stress patterns of spoken warnings. Two different simple scores that might be used in warnings, such as compliance scores and effectiveness score, are also presented. The effective score is useful for determining the need of providing a warning for a particular referent and the compliance score is used for modeling the relationship between warning design and compliant behavior. With all these, the authors try to provide the framework for an appropriately broad approach to the issue of warning design for developing specific warning-related theory and modeling. This book targets industrial practitioners as well as researchers from academic institutes, and provides abundant useful information for those who are interested in this newly emerging topic in industrial and cognitive ergonomics.
In the first chapter, the authors argue that the warning itself is an artifact and it is a representation of the risk or hazard associated with the referent. Unfortunately the mapping of urgency of warnings with their referents are usually very poor in practice. Results on arousal strength of the alerting components such as speed, pitch, colors, and words of warnings in visual and auditory warning were generally reviewed by the authors. The final issue of discussion in this chapter is on the complexity and difficulty of testing nearly 100 variables influencing compliance of warning and the selection of a subjective measure for evaluating the compliance. Readers might find interesting a hypothetical experiment showing effects of changes in pitch and loudness on the perceived urgency of auditory warnings.
As discussed in the second chapter, color is the most obvious iconic feature and it was shown to interact significantly with signal words. Extensive research was done independently on each of these two variables. The practitioners might be happy to know that the demographic stability of some common signal words was affirmed in studies tested with children and college students. One noteworthy point brought out by the authors is that the differences between Warning and Caution are confusing in terms of the relative hazard-