Part 1 -- Welcome To The Revolution
Part 2 -- Some History
Part 3 -- The Revolution Begins
Part 4 -- Page Five In Detail
Part 5 -- Enough Exposition, Let's Get Down To It...
Part 6 -- Digging Deeper
Part 7 -- Looking At The Fine Print
Part 8 -- Confidence Is Not the Only Issue
Some 29% of the sentences in the Iran National Intelligence Estimate (NIE) do contain Words of Estimative Probability (WEPs), however. As the chart below shows, this is pretty much in line with other NIEs. The chart outlines the number of uses of a particular word in an estimative sense in each of the eight NIEs I examined. Again, I only looked at the words in the Key Judgments (not in any of the prefatory matter or in any of the full text or appendices). The column on the far right shows the percent of the time a particular WEP showed up in NIEs generally. In other words, "probably" was used in 33 sentences and there were 263 sentences total in the 7 NIEs examined, so it showed up about 13% of the time. I am also well aware that such a simple review is fraught with difficulty given the complexity of the English language but, since I am only looking for broad trends, I believe that such a review is an appropriate method for analyzing the way in which these estimates were written and the way in which they are changing.
In fact, the Iran NIE is well within the range of other NIEs with respect to percent of sentences containing WEPs. Furthermore, the Iran NIE does not use any “unauthorized” WEPs. That is to say, only WEPs specifically listed on the Explanation of Estimative Language (EEL) page are used in the Iran NIE. This was not the case in previous NIEs which used (though not often) statements that were undefined at a minimum and misleading at their worst. Consider the use of “most likely” in the August 2007 update to “Prospects for
- We judge such initiatives are most likely to succeed in predominantly Sunni Arab areas, where the presence of AQI elements has been significant, tribal networks and identities are strong, the local government is weak, sectarian conflict is low, and the ISF tolerate Sunni initiatives, as illustrated by Al Anbar Province.
“Most likely” could mean many things in this context since there is no baseline probability with which to compare it. The initiatives referenced in the report could be likely to succeed or unlikely to succeed; the reader cannot know from the text. All we can know is that they are "most likely" to succeed in the predominantly Sunni areas. Other formulations, such as “much less likely” and “increasingly likely”, suffer from the same problem. “Not likely” is the only place where I am clearly quibbling as it is obviously synonymous with unlikely. I just think it is silly to state that the authors intend to use “unlikely” on page 5 (the EEL page) and then ignore that and use “not likely” in the text. If the two are truly synonymous then use the one you said you were going to use. If they aren’t synonymous, then explain the difference. You can’t have it both ways.
Beyond the mere use of WEPs, there also appears to be an issue with which WEPs predominate. Again, there is a strong pattern – the clear preference over the last 6 public NIEs for the use of the word “probably”. In fact 73% of authorized and 62% of all WEPs used in the last six NIEs are “probably”. It is also interesting to note that the only non-millennial NIE examined, the 1990 Yugo NIE did not use “probably” at all (whether this pattern holds and whether this was a good thing, I will leave to other researchers).
If the analysts involved in these estimates genuinely believe that all these events are “probable” and not somewhat more or less likely then there is little to discuss. The extreme overuse of the term suggests other explanations, however. "Probably" is arguably one of the broadest WEPs in terms of meaning (see Figure 1 in the paper linked here). Fairly clearly it means that the odds are above even chance but it seems open to interpretation from there.
Thus, analysts could be using "probably" as an analytic safe haven. Relatively certain that the odds are above 50% but unwilling to be more aggressive and use a phrase such as “highly likely” or “virtually certain” and unaware or unable to use expressions of confidence to appropriately nuance these more aggressive terms, these analysts default to “probably”. Since the NIE is a consensus estimate combining input from all 16 intelligence agencies, it is also possible that "probably" was the one word upon which everyone could agree; that it represents, essentially, a compromise position. Either way, such a move is “safe” in terms of getting the answer broadly correct but hurts the decisionmaker who, in the end, must take action and allocate resources. If analysts are more certain than they are willing to put in writing, the decisionmaker is deprived of the analysts’ best judgment and will arguably make less informed decisions.
(Note: The statistical analogy to the issue described above is the classic problem of calibration versus discrimination. For additional insights into this issue I refer you to Phillip Tetlock’s book Expert Political Judgment or to this site)
Monday: Part 9 -- Waffle Words And Intel-Speak