Transparency in Risk Communication Graphical and Analog Tools

摘要

Why is it that the public can read and write but only a few understand statistical information? Whyare elementary distinctions, such as that between absolute and relative risks, not better known?In the absence of statistical literacy, key democratic ideals, such as informed consent and shareddecision making in health care, will remain science fiction. In this chapter, we deal with toolsfor transparency in risk communication. The focus is on graphical and analog representations ofrisk. Analog representations use a separate icon or sign for each individual in a population. Likenumerical representations, some graphical forms are transparent, whereas others indiscerniblymislead the reader. We review cases of (1) tree diagrams for representing natural versus relativefrequency, (2) decision trees for the representation of fast and frugal decision making, (3) bar graphsfor representing absolute versus relative risk, (4) population diagrams for the analog representationof risk, and (5) a format of representation that employs colored tinker cubes for the encoding ofinformation about individuals in a population. Graphs have long enjoyed the status of being "wortha thousand words" and hence of being more readily accessible to human understanding than long-winded symbolic representations. This is both true and false. Graphical tools can be just as wellemployed for transparent and nontransparent risk communications.