The principles of how to arrive at good intelligence estimates are not new. Mike McConnell, the director of national intelligence, said last month that he learned them 17 years ago, while serving under Colin Powell, then the chairman of the Joint Chiefs of Staff.
" ‘Look, I have got a rule,’ " he said General Powell told him. " ‘As an intelligence officer, your responsibility is to tell me what you know. Tell me what you don’t know. Then you’re allowed to tell me what you think. But you always keep those three separated.’ "
Three categories: what you know, what you don’t know, and what you think. A good rule of thumb for categorizing information.
(hat tip to CYizzle for the pointer)