An example of an icon array

The 90 individuals forming the group in the upper left-hand corner test positive on Down syndrome (D), and the 40 individuals in the upper right-hand corner test positive on a neural tube defect (N). Yet, most positive tests are false positives; only the two individuals shown in white among each group have the respective clinical condition. Among those who test negative, i.e. the individuals shown in black, there is one pregnant woman whose child will nonetheless have one of these clinical conditions. Reproduced from Kurz-Milcke, E., Gigerenzer, G., & Martignon, L. 2008. Transparency in risk communication: graphical and analog tools. Ann N Y Acad Sci, 1128, 18-28.

The icon array shows a population of 1000 pregnant women who undergo the Triple Test (see Kurz-Milcke 2008). There is no specific technical knowledge required to understand the icon array above other than the medical condition and that it was plotted as a part-to-whole information. Users also need to understand that the denominators shown on pictograms often do not represent the entire population, but only a sample. Moreover, when the information displayed by the icon array is complex, explanation or guidance of its interpretation is required as done in figure above with the accompanying text explanation to make it more interpretable and understandable to the wider audience.