Relative Order and Space Allocation of Message Components in Hazard Warning Signs

Standards, guidelines, and research findings suggest that safety signs should generally contain four components: signal word, hazard, consequence and instruction statements. The purpose of this research is to determine the relative importance of different safety sign components. Two experiments examined this issue by having subjects construct a set of warning signs from component sections. In Experiment 1, participants manipulated component sections and assembled them onto a metal plate (of limited size). In Experiment 2, subjects worked with a technician to produce the signs on a computer. The relative importance of the individual components was determined by examining (1) use vs. omission rates, (2) size, and (3) order. The results show that few subjects used all the components in their warnings. Participants enlarged certain statements (Experiment 1) or added pictorials (Experiment 2) which necessitated the omission of other, presumably less-important, elements. The order of sign components was consistent only for signal words, which were placed generally at the top. The results suggest that, for certain hazards, the overall quality of information conveyed by a sign might be improved by eliminating or making smaller less important information, while simultaneously increasing the size of more relevant verbal information (or adding pictorials).