---
title: "Boyer-Kassem et al.'s conclusion names a scope-limited retreat and an untested POVM fix as the quantum-like program's remaining escape routes"
type: "claim"
status: "seedling"
source_url: "https://arxiv.org/abs/1606.03430"
source_title: "Quantum-like models cannot account for the conjunction fallacy"
source_author: "Thomas Boyer-Kassem, Sébastien Duchêne, Eric Guerci"
source_date: "2016-06-14T00:00:00.000Z"
source_quote: "There is room for possible future experimental research here — a possible line of division to be investigated could be between AB and MA scenarios of conjunction fallacies. But thus, the quantum-like account would loose its generality, which was its strength."
source_tier: 1
audit_status: "capture-verified"
provenance: "Promotion from 10-inbox/raw/2026-07-19-is-the-conjunction-fallacy-failure-of-quantum-like.md, 2026-07-21"
origin: "batch"
derived_from: ["10-inbox/raw/2026-07-19-is-the-conjunction-fallacy-failure-of-quantum-like.md"]
date_created: "2026-07-21T00:00:00.000Z"
writer_model: "claude-sonnet-5"
tags: ["quantum-cognition","conjunction-fallacy","scope-limit","povm","falsifiability"]
audits: ["2026-07-22 claude-opus-4-8"]
---


Boyer-Kassem, Duchêne & Guerci (2016, arXiv:1606.03430) do not present their
refutation
([[claim-boyer-kassem-refutation-rejects-non-degenerate-and-degenerate-models]],
[[claim-conjunction-fallacy-order-effect-account-refuted-generally]]) as an
unqualified end to quantum-like modeling of the [[entity-conjunction-fallacy|conjunction fallacy]]. Their own
conclusion names two live, unresolved escape routes.

The first is a scenario-restricted retreat: rather than claiming quantum-like
models explain the conjunction fallacy in general, a future line of research
could split scenarios by type ("AB" vs. "MA") and claim coverage only of a
subset. The authors are explicit about the cost: "the quantum-like account
would loose [sic] its generality, which was its strength." The second is a
technical extension — replacing the standard projective ("Born rule")
measurement structure with the more general [[entity-povm|Positive Operator-Valued Measure]]
(POVM) formalism from quantum physics, "recently applied to quantum-like
models of cognition." The authors flag this path as already facing "some new
challenges like response replicability," and offer it as a research strategy
to try, not a result they've obtained.

Neither route is described as closed, and neither is described as achieved.
That distinction — a named, plausible repair path vs. a demonstrated repair —
is exactly the gap the vault's open question tracks
([[question-quantum-cognition-conjunction-fallacy-fatal-or-scope-limit]]), and
it's the gap the next claim in this cluster
([[claim-no-rebuttal-found-lebedev-khrennikov-targets-different-question]])
checks against the subsequent literature.

> [!note] Seek's commentary:
> What I'd flag for anyone tempted to read this paper as a closed door: the
> authors wrote their own exit sign. A retreat that costs you your generality
> is still a retreat, not a defeat, and an untested fix is still a fix on the
> table until someone tests it. Restraint like this is worth citing as
> restraint — it's rarer than the refutation itself. — Seek