No primary or academic source was found documenting the claimed ACH–abductive-reasoning similarity; it appears only as uncited Wikipedia assertions

The claim that Heuer's Analysis of Competing Hypotheses resembles abductive reasoning (inference to the best explanation, after Charles Sanders Peirce) circulates widely but was traced, this search, only to bare Wikipedia assertions. Wikipedia's ACH article states in its lead, with no <ref> in the raw wikitext, "Abductive reasoning is an earlier concept with similarities to ACH." A second article ("Abductive reasoning") repeats the pattern — "In intelligence analysis, analysis of competing hypotheses and Bayesian networks, probabilistic abductive reasoning is used extensively" — also uncited at the point of claim. Two separate articles assert the relationship; neither grounds it.

The two places the link would most plausibly be documented are silent. Heuer's own account of ACH's foundations names "cognitive psychology, decision analysis, and the scientific method" and never uses "abduct" in any form (see claim-heuer-grounds-ach-in-cognitive-psychology-decision-analysis-scientific-method); the CIA's institutional lineage narrative traces ACH to epistemology and the Nosenko case, not to Peircean inference (claim-cia-traces-ach-origin-to-nosenko-case-not-ai). The one peer-reviewed study to engage ACH's theoretical position most closely reaches for Bayes, not abduction (claim-dhami-2019-ach-study-compares-ach-to-bayes-not-abduction).

The only real citation near the topic is narrower than the general claim: Wikipedia's "Weaknesses" section credits Elsaesser & Stech (2007) with using "state-based hierarchical plan recognition (see abductive reasoning)" — but this describes ACH-CD, a derivative MITRE counter-deception tool, not Heuer's method, and the chapter's primary text returned HTTP 403 on every retrieval this session ([unverified-mechanism — needs primary]; see question-verify-elsaesser-stech-2007-ach-cd-abduction).

This is the companion negative finding to claim-no-documented-comparison-of-ach-to-backward-chaining, and another instance of the bare-assertion pattern named in claim-wikipedia-amari-sgd-citogenesis. It remains [unverified — could not confirm or deny after search]: leads (Jones 2017; the NCSU "ACN" blog; Heuer's full 1999 book) went unread. See moc-argument-from-silence and the answering thread at question-ach-abduction-primary-source.