How can warning effectiveness be improved? Research has demonstrated that the inclusion of symbols can help a warning sign or label to attract attention in the first place (see Wogalter et al., 1997). Symbols also facilitate warning communication by conveying large amounts of information (relative to text occupying similar surface area) and avoiding problems associated with varying language and reading abilities. Symbols can be viewed from greater distances than text and may be more distinct and more memorable. However, warning symbols are often poorly understood (see, for example, Davies et al., 1998, Wolff and Wogalter, 1998 and Lesch, 2003).