Words of estimative probability

Words we use to communicate uncertainty.

Sherman Kent
Sherman Kent was a CIA analyst in the Cold War and promoted a scheme of probabilities for specific words and phrases. This is the scheme used in Agile's Risk* mobile app.

Pete Rose
This is Figure 18 in Rose (2001 ).

Rose's consulting firm performed a study similar to the O'Brien paper mentioned below. They reported on it in McLane et al (2008). Here (right) they report on the range of confidence levels associated with words and phrases:

IPCC
The Intergovernmental Panel on Climate Change has recommended some language for communicating likelihood.

Meta-ambiguity
O'Brien (1989 ) reported on the inherent ambiguity of WEPs in general medical practice. He interviewed 56 doctors about twenty-three words and phrases, asking them to place them on a probability scale. He then used the interquartile range of the responses as an indication of ambiguity. O'Brien also compared the interquartile range to a 3-point rating of ambiguity, as given by the respondents. Here's how his data plot: