Developed by Sherman Kent (Words of Estimative Probability, 1964), later fixed for United States intelligence analysis in the 2015 revision of Intelligence Community Directive 203.
A fixed vocabulary that ties each probability word, from almost certain to almost certainly not, to a numeric range, so writer and reader mean the same odds.
When to reach for it
A forecast, risk register, or board memo that relies on words like likely or possible, which different readers will hear as very different odds.
How it runs
- Adopt one published scale of probability words and ranges.
- Choose the matching word for every probability claim.
- Use numeric ranges where precision is warranted.
- Share the scale with readers so they read the words as meant.
Where it sits in SOLVE eX
Go to the source
- Words of Estimative Probability, Studies in Intelligence 8(4), 1964
- Intelligence Community Directive 203: Analytic Standards, Office of the Director of National Intelligence, signed 2 January 2015; it supersedes the 2007 directive, which set no fixed likelihood terms, 2015