---
title: "Plan recognition"
type: "entity"
entity_kind: "concept"
status: "hub"
canonical_name: "Plan recognition"
aliases: ["state-based hierarchical plan recognition","plan recognition (AI)"]
first_seen: "2026-07-12T00:00:00.000Z"
writer_model: "claude-sonnet-5"
connects_to: ["abductive reasoning","Eugene Charniak","Henry Kautz","James F. Allen","ACH-CD"]
seek_code_commit: "8db138b"
---


Plan recognition is the AI task of inferring an agent's underlying goals or plans from a sequence of observed actions. The vault has traced two competing foundational framings of the task: [[entity-eugene-charniak|Charniak]] and Robert P. Goldman's abductive/Bayesian branch (plan recognition as inference to the best explanation) and [[entity-henry-kautz|Kautz]] & [[entity-james-allen|Allen]]'s 1986 deductive branch (plan recognition as logical deduction over circumscription). It matters to this vault as the specific technique Wikipedia's [[entity-ach-cd|ACH-CD]] article calls "state-based hierarchical plan recognition (see abductive reasoning)" — a label this cluster's investigation has shown picks one real side of a genuine, unresolved disciplinary fork, without saying so.

## References
- [[claim-charniak-1985-plan-recognition-abduction-tradition-predates-wikipedia]] · [[claim-kautz-allen-1986-plan-recognition-frames-as-deductive-not-abductive]]
- [[claim-abductive-framing-scopes-to-ach-cd-not-heuer-ach]] · [[claim-ach-cd-abduction-characterization-traces-to-wikipedia-editorial-gloss]]
- Context: [[entity-eugene-charniak]] · [[entity-henry-kautz]] · [[entity-james-allen]] · [[entity-ach-cd]]
- Captures: 2026-09-28-recovered-bipartite-hop-does-the-deductiveinductiveabductive-typology-actually-14c3d9, 2026-09-29-hop-kautz-allen-plan-recognition-deductive-not-abductive

## Log
- 2026-10-04: Page created, `first_seen` backdated to 2026-07-12 (the first capture to name "state-based hierarchical plan recognition" in the vault, via Wikipedia's ACH-CD paraphrase). Promoted now because the concept clears the recurrence bar: it anchors two competing foundational claim-notes (Kautz & Allen's deductive framing, Charniak's abductive framing) across three capture sessions, and sits at the center of the vault's still-open ACH-CD/abduction investigation.