REVIEW 3 major objections 4 minor 30 references
Endoscopic VQA models can score high on complex answers while failing the component questions on the same image, and a training-free method that reconciles the two narrows the gap.
Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →
T0 review · deepseek-v4-flash
2026-08-01 16:50 UTC pith:AN3LDZKG
load-bearing objection The inconsistency finding is real and the ASR ablation is honest; EndoCA is a useful benchmark for endoscopic VQA, but it needs a public release and human validation of its label-conformance scorer before the reliability claims fully convince. the 3 major comments →
Measuring and Improving Complex-Atomic Answer Consistency in Endoscopic VQA
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The paper introduces EndoCA, a paired complex-atomic consistency benchmark built from an existing two-level endoscopic VQA resource, and uses it to argue that complex-answer accuracy alone is an incomplete signal. On 11 vision-language models, the benchmark's joint accuracy—requiring the complex answer and every separately generated atomic answer to be correct—runs well below complex-answer accuracy, and its complex-atomic inconsistency metric shows that a substantial share of accepted complex answers are accompanied by at least one wrong atomic prediction on the same image. The same paired signal motivates ASR, a training-free reconciliation mechanism: the model first answers the atomic que
What carries the argument
The paired evaluation unit—an image, a complex question, its complex answer annotation, and an associated list of atomic question-answer pairs—with a fixed question-type-aware scorer and four metrics: complex-answer accuracy, atomic-answer accuracy, joint accuracy, and complex-atomic inconsistency. Joint accuracy and complex-atomic inconsistency are the load-bearing quantities: they convert the question 'is the final answer right' into 'is every component judgment on the same image right, and do the two agree.' The reconciliation mechanism ASR reuses this structure, treating model-generated atomic answers as premises for a revision prompt and for a consistency-judged answer/abstain decision.
Load-bearing premise
The whole inconsistency metric assumes that every correct complex answer can be exactly decomposed into the atomic labels inherited from the source dataset, so a semantically correct paraphrase that does not align with those labels is counted as inconsistent.
What would settle it
Collect or construct a set of complex answers that clinicians judge clinically correct but that do not exactly match the inherited atomic label sets; recomputing the metrics with a lenient semantic-match rule would show whether the benchmark's gap and ASR's 10.4-point inconsistency reduction are genuine or partly artifacts of the exact-match scorer.
If this is right
- Endoscopic VQA evaluation should report joint accuracy and complex-atomic inconsistency alongside complex-answer accuracy whenever paired atomic questions exist; otherwise rankings and reported reliability can mislead.
- Models with nearly identical complex-answer accuracy can differ by more than 14 percentage points in joint accuracy, so consistency-aware scores reorder model comparisons.
- As question complexity rises—more atomic components per complex question—all-atomic accuracy falls faster than complex accuracy, making multi-part questions a stress test of paired correctness.
- Model-generated atomic answers can serve as inference-time premises for revision without retraining, improving paired correctness on top models.
- Consistency-guided abstention provides a reliability–coverage trade-off, letting models answer more often when atomic premises agree and abstain when they conflict.
Where Pith is reading between the lines
- The benchmark's inconsistency score is defined under exact normalized matching to inherited atomic labels; a lenient semantic-match scorer might shrink the reported gap, so the gap's magnitude is partly a function of scoring strictness, not only model behavior.
- The ASR pattern—answer components, then reconcile or abstain—could transfer to other multi-component medical VQA settings such as radiology or pathology wherever atomic subquestions exist; the paper does not test this.
- The abstention signal could double as a human-review trigger in clinical deployment: cases where atomic premises conflict are exactly the ones a clinician should re-check.
- Because ASR uses only the model's own outputs, its gains could in principle generalize across architectures; a natural extension is to test whether fine-tuning on consistency pairs shrinks the gap more durably than inference-time reconciliation.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper introduces EndoCA, a paired complex-atomic answer consistency benchmark for endoscopic VQA, built from the two-level QA structure of Kvasir-VQA and Kvasir-VQA-x1. Each test sample pairs a complex question with its associated atomic questions; complex-answer correctness is defined by the EndoCA scorer as normalized exact agreement with all associated atomic annotations. The paper evaluates 11 VLMs and reports complex accuracy, atomic accuracy, joint accuracy, and complex-atomic inconsistency. It finds that several models achieve high complex-answer accuracy while showing materially lower joint accuracy and non-negligible complex-atomic inconsistency. It then proposes Atomic-Support Reconciliation (ASR), a training-free method that uses the model's own atomic answers as contextual premises for revising complex answers and for consistency-guided selective answering. On four models, ASR-Revise improves joint accuracy by +3.1 to +8.1 percentage points and reduces complex-atomic inconsistency by 10.4 points on average; ASR-Selective trades coverage for answered-subset accuracy.
Significance. If the EndoCA scorer is accepted as valid, this is a useful benchmark contribution: it provides a reproducible, fixed-protocol metric for a clinically relevant reliability gap, evaluates a broad and representative set of VLMs, includes a controlled complexity axis, and proposes a training-free mitigation with a clean ablation that separates atomic-premise revision from generic self-checking. The paper is careful to report four complementary metrics and to distinguish complex-answer accuracy from paired correctness. However, the central claim is contingent on the validity of the EndoCA scoring rule, and the current manuscript provides no human-agreement or paraphrase-sensitivity validation for arbitrary model outputs. Since the ASR method is also evaluated with the same scoring rule, the headline 'hidden inconsistency' numbers and the ASR gains could partly reflect label-conformance rather than genuine unreliability or improvement. These concerns are addressable with targeted experiments, and the strengths of the benchmark design justify a revision rather than rejection.
major comments (3)
- [Section III-C, Eq. (2)-(3), Table II] Section III-C and Eq. (2)-(3) define complex-answer correctness as normalized exact agreement with every associated atomic annotation, but Table II's worked example describes the scorer as 'extract[ing] component labels' from a free-form sentence ('visible text is present' becomes 'yes'). These two descriptions conflict. If the scorer performs semantic component extraction, the exact-match wording and the claim that no additional LLM judge is used are incomplete; if it only applies surface normalization, the example overstates what is checked. This matters because the paper's headline phenomenon—complex accuracy hiding inconsistency—and the ASR gains in Table V are both measured with this scorer. No human-agreement study is reported; the source-dataset construction-time agreement does not validate scoring of arbitrary model outputs. I request a precise specification of the matching/extra
- [Section IV-B, Tables V-VI] ASR-Revise conditions the revision on Pi = {(qij, a_hat_ij)}, the model's own atomic answers, while the EndoCA scorer checks complex answers against the associated atomic annotations. The reported +3.1 to +8.1 joint-accuracy gains and −10.4 average inconsistency reduction may therefore reflect the revised answer conforming to the premise-label format rather than a genuine improvement in evidence use. The no-atomic ablation (Table VI) isolates the presence of atomic premises, but it does not test whether the benefit comes from independent evidence reconciliation or label-copying. Please add controls in which the atomic premises are (i) another model's atomic answers and (ii) deliberately corrupted atomic labels; report whether the revised answers follow the premise labels, and whether the joint-accuracy gain persists under human or semantic scoring.
- [Section V-C, Table V] ASR-Selective is evaluated only by coverage and accuracy on the answered subset, without a comparison at matched coverage. Direct has 100% coverage, so the 71.0% versus 63.3% comparison does not separate the benefit of abstaining from the benefit of selecting easy cases. The claim that ASR-Selective 'improves accuracy on answered cases' should be supported by a risk-coverage curve, by direct accuracy at the same coverage (for example, random or confidence-based selection), or by a calibrated selective-prediction metric. Without this, the selective-answering contribution is not yet fully established.
minor comments (4)
- [Throughout] There are LaTeX rendering issues: 'atomicquestion' should be 'atomic question', and 'LLaV A-Med' should be 'LLaVA-Med'. Please check all model names for consistent typography.
- [Tables III-V] No confidence intervals or significance tests are reported. Given deterministic decoding and large fixed sample sizes this may be acceptable, but the authors should state explicitly that all metrics are point estimates over a fixed benchmark and that no repeated trials were run.
- [Table V] Table V reports only deltas for Joint Acc. and Complex-Atomic Inconsistency. It would help the reader to also show the absolute Direct and Revised values for these two metrics, or to include a note that the Direct values are those in Table III.
- [Section VI] The conclusion concedes that the current protocol is tied to atomic decomposability and defers free-form clinical questions to future work. This limitation should appear earlier, in the benchmark construction or scoring section, so readers interpret the metric accordingly.
Circularity Check
No circularity: EndoCA's metrics are transparent definitions and ASR's gains are empirical; scorer validation is a correctness risk, not a circular step.
full rationale
EndoCA is a measurement protocol, not a derivation: its central quantities (C_i, A_ij, joint accuracy, inconsistency) are defined transparently in Eqs. (2)-(6). Complex-answer correctness is explicitly a label-conformance rule (Section III-C: 'A complex prediction is counted as correct only when the normalized answer matches every associated atomic answer annotation'), but the paper does not claim to derive complex correctness from atomic correctness; it empirically probes the same models with separately generated atomic prompts. The headline claim that complex-answer accuracy can hide inconsistency is a contingent empirical result from Tables III-IV, not a consequence of the definitions: nothing in Eq. (3) forces the separate atomic predictions A_ij to fail when C_i=1, and the measured inconsistencies vary widely across models (12.5%-83.1%). ASR is a post-processing method that intentionally conditions revision on model-generated atomic premises; its joint-accuracy gains are measured rather than entailed, and the ablation (Table VI) shows that removing atomic premises eliminates the gains. The lack of a human-agreement study for the scorer is a validity/correctness limitation, and the conclusion explicitly defers free-form clinical questions, but these do not make the empirical claims circular. No fitted parameter is renamed as a prediction, and no load-bearing self-citation or imported uniqueness theorem is present.
Axiom & Free-Parameter Ledger
axioms (4)
- domain assumption Kvasir-VQA and Kvasir-VQA-x1 annotations are correct ground truth for the endoscopic images, and the recorded complex-to-atomic associations are valid.
- ad hoc to paper A correct complex answer is fully captured by the set of associated atomic answer annotations under the fixed scorer.
- domain assumption The fixed question-type-aware scorer's normalization rules preserve semantic equivalence for all model outputs.
- domain assumption Model-generated atomic answers, when provided as revision premises, do not leak the scoring structure in a way that trivially inflates ASR gains.
read the original abstract
Endoscopic visual question answering (VQA) increasingly asks complex questions that combine several endoscopic answer components rather than isolated factual queries. Such complex answers may be scored as correct even when the same model fails on associated atomic questions. We introduce EndoCA, a paired complex-atomic answer consistency benchmark for evaluating whether complex answers remain consistent with same-image atomic answers. EndoCA contains two suites: EndoCA-Core evaluates compact question-complexity patterns commonly seen in practical endoscopic VQA, and EndoCA-Diagnostic supports controlled analysis across increasing question complexity. We evaluate 11 VLMs spanning open, medical, endoscopy-adapted, and closed-source models on EndoCA. Some VLMs achieve high complex-answer accuracy, yet their atomic-answer accuracy and complex-atomic answer consistency remain substantially lower. To reduce this complex-atomic inconsistency, we introduce Atomic-Support Reconciliation (ASR), a training-free mechanism that uses model-generated atomic answers as contextual premises for answer revision and consistency-guided selective answering. On four selected publicly available models, ASR-Revise improves paired complex-atomic correctness with modest changes in complex-answer accuracy, while ASR-Selective improves accuracy on answered cases by allowing the model to abstain from less reliable cases. Together, EndoCA and ASR provide a consistency-aware benchmark and a training-free mechanism for answer reconciliation and selective answering in endoscopic VQA.
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