The Effect of Symbols on Warning Compliance

Abstract

The present study investigated whether different warning designs, specifically those with symbols, affect compliance rates. Five conditions were tested: a verbal warning, a pictographs warning with a circle enclosing each graphic, a pictographs warning with a triangle on its vertex enclosing each graphic, a warning with both words and pictographs (triangular enclosures), and a control (no warning). Participants performed a chemistry laboratory task using a set of instructions that contained one of the five conditions. The warnings instructed them to wear safety goggles, mask and gloves. All four warning conditions had significantly greater compliance than the no-warning condition. The highest rate of compliance occurred with the verbal plus pictographs condition, although it did not differ significantly from the verbal condition. A significant main effect was found for the “presence of pictographs” variable, suggesting that the addition of pictographs to a verbal warning will increase compliance rates. The unexpected finding that the pictographs warning with triangular enclosures had significantly lower compliance means than the verbal warning may be due to the different types of message modes or design criteria used. The enclosure shape made no difference in compliance rates, despite research that indicates that unstable shapes are preferred as warning enclosures. The results suggest the importance of conducting behavioral studies rather than relying on preference data.