The book Pearl Harbor: Warning and Decision (1962) by Roberta Wohlstetter is a fast-paced, scholarly, thoughtful analysis of signals and noise, of historical lessons, and of human cognitive issues — all told in the context of the surprise Japanese attack of 1941-12-07 that brought the United States into World War II. Wohlstetter's thesis is summarized in her "Introduction":

The popular view endows the activity of obtaining secret information with great risks and considerable drama. The hazards of interpretation, of selecting the relevant signs from the wealth of public and secret data, are scarcely understood. The leap of inference, however, if less dramatic, has great perils of its own.

In particular, the public image of warnings for the impending Pearl Harbor disaster appears to be highly simplified, with outlines clearly marked and with few shadings. The record is full of references to supposedly unambiguous indications of the Japanese plan. The MAGIC message "East Wind Rain" is one of the most famous. But, in fact, the signal picture in the limited locale of Honolulu is amazingly complex, and the mass of signals grows increasingly dense and freighted with ambiguities as we move to the larger assemblage of agencies in Washington. In both places signals announcing the Pearl Harbor attack were always accompanied by competing or contradictory signals, by all sorts of information useless for anticipating this particular disaster. We refer to these competing signals as "noise." To understand the fact of surprise it is necessary to examine the characteristics of the noise as well as the signals that after the event are clearly seen to herald the attack.

If it does nothing else, an understanding of the noise present in any signal system will teach us humility and respect for the job of the information analyst. ...

... further insightful quotes to follow.

(cf. Pearl Harbor: Warning and Decision in Wikipedia, and Science and Pseudoscience (2001-10-06), Expert Political Judgment (2010-05-13), Signal and Noise (2012-12-25), ...) - ^z - 2017-10-20