Kautz & Allen's 1986 foundational plan-recognition paper frames itself as deductive inference, never abductive

abductive-reasoningplan-recognitioncircumscriptionach-cdai-historyargument-from-silencehenry-kautzjames-allen

Henry A. Kautz and James F. Allen's "Generalized Plan Recognition" (AAAI-86 Proceedings, pp. 32–37) is the field's foundational theory of plan recognition — inferring an agent's goals and plans from observed actions. The paper states its own framing directly: "that plan recognition be viewed as ordinary deductive inference." The mechanism is McCarthy's circumscription, a nonmonotonic formalism for minimizing the set of explanations consistent with observations within a closed-world action taxonomy — explicitly contrasted in the paper with "probabilistic inference." Across the paper's six pages, the words "abduct," "abduction," and "abductive" do not appear once.

This matters because later secondary literature — including Wikipedia's characterization of "state-based hierarchical plan recognition (see abductive reasoning)," the technique's own descendant terminology — routinely calls plan recognition "an abductive reasoning task." The vault had already traced that Wikipedia parenthetical to an uncited editorial gloss rather than a quoted claim (claim-ach-cd-abduction-characterization-traces-to-wikipedia-editorial-gloss), and separately established that even a generous reading of Elsaesser & Stech's ACH-CD chapter would only describe a MITRE counter-deception derivative, not Heuer's ACH (claim-abductive-framing-scopes-to-ach-cd-not-heuer-ach). This note goes one layer further: at the actual 1986 AI-literature source of the mechanism Wikipedia glosses, the authors themselves reject the abductive framing in favor of deduction over a circumscribed model. It is an independent negative finding on the argument-from-silence ledger, corroborating from the mechanism side what the earlier notes corroborated from the citation-genealogy side — see also claim-no-primary-source-documents-ach-abduction-similarity and the general scope-of-abduction claim in claim-inference-logical-types.