A framework book by Richards J. Heuer Jr., a 45-year veteran of the CIA, on how to make sense of complex situations using a structured intelligence analysis methodology. The book explains how analysts think, why they make mistakes, and how they can improve their judgment in high-stakes, uncertain environments. Heuer details the mental shortcuts, assumptions, and cognitive limitations that can lead to flawed analysis, and he emphasizes the importance of trying to disprove hypotheses rather than confirm them. He introduces Analysis of Competing Hypotheses (ACH), an eight-step framework grounded in cognitive psychology, decision analysis, and the scientific method. ACH forces analysts to identify all plausible hypotheses and test each against the available evidence, allowing the hypotheses that have not been disproved by the available evidence to survive instead of evaluating one favored explanation in isolation.