RT Journal Article SR Electronic(1) A1 Adams, Austin A1 Boersema, Theo A1 Mijksenaar, Meijer YR 2010 T1 Warning symbology: Difficult concepts may be 
successfully depicted with two-part signs JF Information Design Journal VO 18 IS 2 SP 94 OP 106 DO https://doi.org/10.1075/idj.18.2.01ada PB John Benjamins SN 0142-5471, AB Symbol signs ­– signs without words – are often used to communicate safety or public information messages. The International Organization for Standardization (ISO) provides standards ISO 3864-1 and ISO 3864-3 giving design principles for both graphical symbols and completed signs in the safety arena. The present study shows that for difficult signage circumstances a two-part sign, showing the desired and undesired circumstances with a tick and a cross, can be much more effective than the normal single-part sign provided for by these ISO standards. The present study also suggests that ISO’s sign assessment methods could be efficiently combined and simplified., UL https://www.jbe-platform.com/content/journals/10.1075/idj.18.2.01ada