What Do Words Of Estimative Probability Mean? (Part 1 -- Introduction)

(Note: This is another attempt at what I call "experimental scholarship" (See this series for my first attempt). The discussion regarding the use of blogs as a way to publish scholarly works (or, in my case, more-or-less scholarly works...) is pretty hot and heavy right now. However, I found writing an article in the form of a series of blog posts extraordinarily useful the first time, if only for the comments that I received that I am sure will make any traditional journal article just that much better. It was the positive feedback I received from that experience that makes me want to give it another go.)

I was cleaning my office this week in anticipation of a new term (we are on a quarter system at Mercyhurst) and I ran across the results of a classroom exercise I conduct regarding the meaning of words of estimative probability (such as “likely” or “virtually certain”) or as they are commonly referred to around here, WEPs. I thought some discussion of the exercise I use and the results of that exercise would be of interest to intelligence studies students and educators.

The value of WEPs is, of course, an ongoing question both within the intelligence community and among its critics. At one end of the spectrum are those, like Michael Schrage, who call for numeric estimates -- x has a 75% chance of happening plus or minus 10%, that sort of thing. At the other end of the spectrum are those who Sherman Kent called “poets” who believe that it doesn’t matter what an analyst says, policymakers and others will interpret the analysis however they wish. The intelligence community (IC) has recently moved further in the direction of a position that, while not quite as extreme as Schrage’s, is clearly on that side of the spectrum as the “best practice” for effectively communicating the results of intelligence analysis to decisionmakers.

Much of the reason for using WEPs instead of numbers centers around the imprecise nature of intelligence analysis in general, coupled with the misunderstandings that could arise in the minds of decisionmakers if analysts used numbers to communicate their estimative judgments. A large part of the argument against WEPs, on the other hand, has to do with the imprecise meaning of the words themselves. In other words, what exactly does ‘likely” mean? That is where I intend to go next.

Tomorrow -- To Kent And Beyond!