Words or numbers? Communicating probability in intelligence analysis.

Intelligence analysis is fundamentally an exercise in expert judgment made under conditions of uncertainty. These judgments are used to inform consequential decisions. Following the major intelligence failure that led 2003 war Iraq, organizations implemented policies for communicating probability their assessments. Virtually all chose convey using standardized linguistic lexicons which ordered set select terms (e.g., highly likely) associated with numeric ranges 80-90%). We review benefits and drawbacks this approach, drawing on psychological research communication studies have examined effectiveness lexicons. further discuss how probabilities can overcome many shortcomings probabilities. Numeric not without they more difficult elicit may be misunderstood by receivers poor numeracy). However, these ameliorated training practice, whereas pitfalls endemic approach. propose that, balance, outweigh drawbacks. Given enormous costs failure, community should reconsider its reliance Our discussion also has implications other domains such as climate science.