ACH-CD (Analysis of Competing Hypotheses – Counter Deception)

ACH-CD is a modified variant of Heuer's Analysis of Competing Hypotheses, built at MITRE by Christopher Elsaesser and Frank J. Stech specifically to address analysts' cognitive vulnerabilities to deception. It is distinct from Heuer's original ACH — a downstream, purpose-built derivative — and is the tool to which the widely-circulated "abductive plan recognition" characterization actually attaches. It matters to the vault as the pivot of the ACH↔abduction question: the one real citation in that neighborhood describes ACH-CD, not ACH proper.

References

• claim-abductive-framing-scopes-to-ach-cd-not-heuer-ach — the abductive framing scopes to ACH-CD, not to Heuer's ACH.

• claim-ach-cd-abduction-characterization-traces-to-wikipedia-editorial-gloss — the abductive label is a Wikipedia editorial gloss, not a chapter quote.

• claim-elsaesser-stech-detecting-deception-chapter-bibliographically-corroborated — the primary chapter (Elsaesser & Stech, 2007), bibliographically corroborated but unread.

• claim-no-primary-source-documents-ach-abduction-similarity — the broader negative finding on the ACH↔abduction link.

• question-verify-elsaesser-stech-2007-ach-cd-abduction — the open verification thread.

• 2026-10-04: The "abductive plan recognition" label isn't an arbitrary editorial classification — it picks a real, named, decades-old AI research tradition (Eugene Charniak, 1985, formalized with Goldman in 1993) that genuinely calls itself abductive, in print, independent of and before Wikipedia's article existed. That tradition sits opposite an equally foundational deductive framing of plan recognition (Kautz & Allen, 1986) that explicitly rejects abduction. So the label is a real concept, picking one side of a genuine disciplinary fork — but which side, if either, Elsaesser & Stech's own chapter actually follows is still unconfirmed (claim-charniak-1985-plan-recognition-abduction-tradition-predates-wikipedia, observation-inference-logical-types-ach-cd-abduction-pairing-is-confirmed-charniak-bridge; open thread unchanged at question-verify-elsaesser-stech-2007-ach-cd-abduction).