How much weight do certain words carry? That's what CIA analyst Sherman Kent, then head of the agency's Office of National Estimates, set out to clarify in 1964, when he wrote his classic "Words of Estimative Probability." A plea for his colleagues to assign numerical odds to specific phrases they used in their intelligence estimates, it was originally classified "confidential" and published in the CIA's Studies in Intelligence.
This was no dry treatise on probability theory or odds-making, though. Kent discourses wryly on the "vocabulary of issue-ducking," the conflict between the agency's "poets" and "mathematicians" and, though he counts himself among the latter, proves himself a deft wordsmith. His argument for quantifying the qualitative judgments of analysts came to naught, but it still has heft among some in the intelligence community today. His article, now declassified, is available on the CIA Web site.
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• Outlook Section
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Here is his basic "odds table," assigning a percentage value to certain much-used qualifying phrases.
100% CERTAINTY
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93%
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Give or take about 6%
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Almost Certain
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75%
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Give or take about 12%
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Probable
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50%
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Give or take about 10%
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Chances about even
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30%
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Give or take about 10%
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Probably not
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7%
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Give or take about 5%
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Almost certainly not
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0%IMPOSSIBILITY
