How to convey uncertainty

February 3, 2009

In current issue of Psychological Science:

Improving Communication of Uncertainty in the Reports of the Intergovernmental Panel on Climate Change
David V. Budescu, Stephen Broomell, and Han-Hui Por
When communicating information about uncertainty, the use of probability terms such as “unlikely,” “likely,” “probable,” or “virtually certain” may lead to confusion and errors. Participants assigned numerical values of probability to such terms used in a major 2007 report on climate change. Despite having access to the author panel’s guidelines for interpreting probability terms, respondents significantly overestimated the amount of imprecision in the climate-change findings being conveyed. An alternative approach to communicating uncertainty—one whose precision matches the precision of the evidence—would improve readers’ understanding of the findings and thereby enhance the foundation for sound policy decisions.

Relevant in many places including in particular intelligence analysis.