AI Study
Notes on trustworthy AI and the clinical knowledge that informs my research.
Three parts, in the order they build on each other, and the ontology that ties them together.
Probability & Statistical Inference
Linear Algebra & Optimization
Signals, Systems & Transforms
Learning Models & Representation
Feedback Control & Classical Design
Decision Making & Reinforcement Learning
Efficient Computation & Acceleration
Clinical Foundations & Systemic Disease
Hepatobiliary Medicine & Imaging
Neurology & Sleep Medicine
Oncology
Evaluation, Generalization & Reliability
Causality, Bias & Shortcuts
Clinical Alignment & Interpretability
Evidence Auditing
Medical AI Systems & Deployment
Gallbladder AI: Applied Research
Concepts by type around the ring, and every edge an assertion about what holds between them. Hover an edge to read the claim. The corpus graph shows instead which writing discusses which concept.
Ontology
The knowledge graph records which of these notes discusses which concept. This is a different thing: what kind of entity each concept is, and what I hold to be true between them. Every line below is an assertion, so every line is disputable, and the ones resting on published work carry the source. 195 assertions over 101 concepts, in 13 relations.
assessesProperty
Method · Metric → Property
Provides a procedure or numerical assessment of the property, without establishing it conclusively.
- Auditing assessesProperty Faithfulness A frozen-model explanation audit compares the readout's stated importance against the behaviour it purports to explain. no source asserted
- Intervention & ablation assessesProperty Faithfulness Controlled perturbations compare attribution-predicted effects with actual score changes, conditional on the perturbation design. arXiv:1901.09392
- Evaluation metrics assessesProperty Calibration Calibration measures quantify the discrepancy between predicted probabilities and observed frequencies in a specified population. arXiv:1706.04599
- Evaluation metrics assessesProperty Faithfulness Scope: explanation-specific metrics, which quantify agreement between attributed importance and responses under a defined perturbation distribution. arXiv:1901.09392
- Auditing assessesProperty Plausibility Blinded clinical review can assess whether an explanation looks reasonable for the task, separately from computational testing. no source asserted
- Subgroup & fairness assessesProperty Calibration Calibration can be assessed within prespecified patient or acquisition groups; this does not establish fairness under every criterion. no source asserted
- Auditing assessesProperty Calibration An audit can compare frozen-model probabilities with independently obtained outcomes on a declared evaluation population. no source asserted
- Exploration & stress testing assessesProperty Robustness Performance under constructed perturbation is the operational assessment of robustness, bounded by the perturbation family chosen. no source asserted
- Sensitivity analysis assessesProperty Robustness Varying one design decision at a time measures how much the reported result depends on it, for the decisions someone chose to vary. no source asserted
- Hypothesis testing assessesProperty Calibration A goodness-of-fit test compares predicted frequencies against observed ones, subject to the test's own independence assumptions. no source asserted
- Intervention & ablation assessesProperty Translation invariance Shifting the input and measuring the output is a direct test of invariance against equivariance. Classification and localization can be served by separate heads, one invariant and one equivariant, so the two requirements need not conflict. arXiv:1605.06409
- Sensitivity analysis assessesProperty Stability margin Sweeping a parameter and locating where behaviour changes qualitatively measures how far the current operating point sits from that boundary. no source asserted
- Identifiability analysis assessesProperty Causal identifiability An identification argument specifies the causal target and checks which assumptions connect it to observations; exchangeability, consistency and positivity are one route for treatment effects, not assumptions verified by predictive accuracy. no source asserted
- Singular value analysis assessesProperty Measurement identifiability For the specified linear forward model y = A*x, a nonzero null-space vector v makes x and x+v observationally identical. Full column rank removes that ambiguity in the noiseless model, but does not validate the model itself. no source asserted
- Singular value analysis assessesProperty Inverse-problem conditioning Inverting a linear forward model divides each observable singular-direction component by its singular value, so small nonzero values amplify measurement error. Regularization can suppress that amplification by changing the estimator, without recovering discarded information. no source asserted
- Control stability analysis assessesProperty Stability margin Given an explicit plant, controller, delay model and perturbation family, pole or frequency-domain analysis can locate a stability boundary. The resulting margin belongs to those dynamics, rather than to a classifier's held-out accuracy. no source asserted
- Diagnostic reasoning assessesProperty Pretest probability The probability before an index test depends on presentation, history and the referral pathway. Prevalence among patients selected for surgery is not automatically the relevant starting probability for a consecutive outpatient examination. no source asserted
- Bayesian decision analysis assessesProperty Clinical utility Expected losses can compare actions under an explicit probability model and clinically justified consequences. This assesses potential value under assumptions; it does not demonstrate that deploying the recommendation improves care. no source asserted
- Reference standard adjudication assessesProperty Clinical validity Checking how labels were established tests whether model outputs are being compared with the intended clinical condition. It includes lesion and time correspondence and whether the reference incorporated the index test, rather than assuming a label name guarantees validity. no source asserted
- Clinical feature annotation assessesProperty Clinical assessability Calling a finding absent requires enough coverage, resolution and appropriate views to assess it. Some findings require a sequence or manoeuvre, so an apparently negative still frame may instead be unassessable. no source asserted
- Clinical feature annotation assessesProperty Clinical evidence reliance Independent feature labels permit comparisons between model behaviour and the clinical evidence available in each case. Correlation or decodability alone remains insufficient; the assessment needs a design that distinguishes feature availability from actual diagnostic use. no source asserted
- Intervention & ablation assessesProperty Clinical evidence reliance A controlled edit can test whether output responds to a nominated clinical finding while preserving competing evidence. The conclusion is conditional on the edit changing that finding without introducing other diagnostic or acquisition changes. no source asserted
- Comparative workflow evaluation assessesProperty Clinical utility Comparing care with and without the intended use of the system can assess effects on decisions, outcomes, harms and workload. A causal interpretation requires a design addressing alternative explanations for differences between the care pathways. no source asserted
- Internal validation assessesProperty Calibration Predictions on held-out patients can be compared with observed frequencies within the sampled setting, accounting for repeated observations per patient. The assessment remains conditional on that population, label process and prediction horizon. no source asserted
- External validation assessesProperty Transportability Evaluating a frozen model and preprocessing pipeline in another specified setting tests performance under that setting's acquisition, case mix and reference process. This directly supports a claim about the evaluated conditions; broader transport requires an additional argument. no source asserted
- Sensitivity analysis assessesProperty Transportability Varying specified acquisition conditions, case mix or prevalence can expose which assumptions a transport claim depends on. Such checks support only the perturbations actually represented; they are not a substitute for evidence from every proposed setting. no source asserted
probesThreat
Method → Threat
Can investigate a hypothesis about the threat; nominating a candidate is not confirming a mechanism.
- Auditing probesThreat Shortcut learning Shortcut hypotheses are explicit audit targets requiring task-specific investigation, not aggregate accuracy. doi:10.1016/S2589-7500(22)00003-6
- Intervention & ablation probesThreat Shortcut learning Controlled changes to suspected non-diagnostic cues reveal predictor sensitivity; shown on COVID-19 radiograph classifiers, not gallbladder models. doi:10.1038/s42256-021-00338-7
- Counterfactual probesThreat Shortcut learning Generative comparisons can expose candidate cues, but coupled edits prevent treating each comparison as an isolated intervention. doi:10.1038/s42256-021-00338-7
- Causal inference probesThreat Confounding An explicit causal model identifies candidate confounding paths relative to an estimand; it does not discover unmeasured confounders. doi:10.1214/09-SS057
- Causal inference probesThreat Spurious correlation Causal analysis separates an observed association from the intervention claim it might be taken to support. doi:10.1214/09-SS057
- Subgroup & fairness probesThreat Shortcut learning Stratifying by suspected cue availability can reveal shortcut-compatible failures; severity and case-mix remain alternative explanations. no source asserted
- Attribution & saliency probesThreat Shortcut learning Attributions nominate suspicious regions for controlled testing; they do not independently establish reliance. doi:10.1038/s42256-021-00338-7
- Exploration & stress testing probesThreat Shortcut learning Deliberately constructed conditions can surface a reliance a fixed suite never sampled; absence of a failure under testing is not absence of the reliance. arXiv:2004.07780
- Exploration & stress testing probesThreat Distribution shift Perturbation and stress conditions stand in for shifts that have not yet occurred, and only for the shifts someone thought to construct. no source asserted
- Sensitivity analysis probesThreat Distribution shift Leave-one-site-out and cohort re-weighting rehearse a shift using variation already present in the assembled data, and reach no further than that variation. no source asserted
- Out-of-distribution detection probesThreat Distribution shift A support or density estimate can flag inputs unlike the training set, for the notion of likeness the model was given. doi:10.1162/089976601750264965
- Sensitivity analysis probesThreat Deployment feedback loop Comparing a prospectively recruited stream against operational data can expose divergence the operational data alone cannot show. no source asserted
- Ensembling probesThreat Distribution shift Members that converged to different modes tend to agree where the data constrained the function and diverge where they did not. The signal is informative but neither guaranteed nor specific to distribution shift. arXiv:2002.08791
- Feedback correction probesThreat Distribution shift Measuring realized outcomes and correcting against them surfaces divergence between deployment and development conditions that an open pipeline never observes. no source asserted
canIntroduce
Method · Threat · EvidenceSource → Threat
Can create or enable the object. Neither inevitability nor sufficient causation is implied.
- Confounding canIntroduce Spurious correlation A common-cause pathway produces association that does not represent the causal effect being estimated. doi:10.1214/09-SS057
- Spurious correlation canIntroduce Shortcut learning An association available in training can support a rule that fails when it changes; learning that rule is not inevitable. arXiv:2004.07780
- Representation learning canIntroduce Shortcut learning Learned representations can privilege easy predictive cues over the evidence the task intends. arXiv:2004.07780
- Ultrasound acquisition canIntroduce Spurious correlation Acquisition and documentation workflows can couple annotations with the target imaged; demonstrated on fetal-ultrasound calipers. doi:10.1007/978-3-031-72111-3_59
- Intervention & ablation canIntroduce Distribution shift Removing or replacing regions at test time creates inputs unlike training data; ROAR answers this by retraining, which changes the question. arXiv:1806.10758
- Screening programs canIntroduce Distribution shift Moving a model from referred symptomatic patients into screening changes eligibility, prevalence and disease spectrum. no source asserted
- Deployment & drift canIntroduce Distribution shift Moving between institutions changes acquisition and patient distributions, as shown for pneumonia models across hospitals. doi:10.1371/journal.pmed.1002683
- Similarity & graph construction canIntroduce Spurious correlation A kernel or affinity matrix asserts which cases count as comparable; if acquisition rather than biology drives that similarity, downstream structure inherits it. no source asserted
- Preprocessing & resampling canIntroduce Spurious correlation Resampling without anti-aliasing can stamp a ratio-dependent texture on an image, and the ratio may follow the acquiring scanner. Whether it appears depends on the signal content and the sampling, so it is a mechanism to rule out rather than a universal artefact. doi:10.1109/CVPR52688.2022.01112
- Deployment & drift canIntroduce Deployment feedback loop A model whose outputs influence the care that generates its next training data appears in its own input distribution. arXiv:2002.06673
- Deployment feedback loop canIntroduce Spurious correlation Under-flagging a subgroup yields fewer confirmed cases in it, which trains the next model to under-flag it further. arXiv:1706.09847
- Objective design canIntroduce Proxy objective Choosing a differentiable stand-in for a non-differentiable evaluation target is what creates the gap; the gap follows from the choice, not from poor execution. no source asserted
- Proxy objective canIntroduce Shortcut learning A shortcut is precisely a solution scoring well on the proxy and badly on the target, so proxy optimization is the mechanism that rewards it. no source asserted
- Objective design canIntroduce Outlier influence A squared residual grants a point influence proportional to its error, so the most anomalous record outweighs many sound ones. doi:10.1214/aoms/1177703732
- Pseudo-labelling canIntroduce Label noise A teacher's outputs become the student's training targets, so the teacher's errors are inherited by construction rather than averaged away. doi:10.1109/CVPR42600.2020.01070
- Pseudo-labelling canIntroduce Spurious correlation Systematic teacher error can propagate or amplify: a subgroup the teacher under-detects can train the student to under-detect it further. Random error does not generally cancel back to the true targets, and amplification is not inevitable either. doi:10.1109/CVPR46437.2021.01139
- Feedback correction canIntroduce Deployment feedback loop Correcting on a system's own measured output is by construction a closed loop. Whether it converges or diverges depends on the gain around it, but naming that gain requires an explicit model of the update rule and its delays. no source asserted
- Histopathology canIntroduce Selection & verification bias When histological verification is available mainly after surgery, restricting evaluation to verified cases conditions on the clinical decision to operate. The resulting case spectrum may differ from that of patients facing the original diagnostic decision. no source asserted
usesEvidence
Method → EvidenceSource · Finding
Observations from the object enter the subject's assessment or reasoning.
- Diagnostic reasoning usesEvidence Sonographic features Observed morphology and acoustic findings feed task-specific reasoning without determining the diagnosis alone. no source asserted
- Diagnostic reasoning usesEvidence Histopathology A matched tissue result can be incorporated while retaining specimen, sampling and timing limits. no source asserted
- Diagnostic reasoning usesEvidence Cross-sectional imaging CT/MRI observations contribute when they address the unresolved clinical question. no source asserted
- Auditing usesEvidence Sonographic features Independently assessed findings can anchor an ultrasound evidence audit; annotations derived from the explanation would be circular. no source asserted
- Auditing usesEvidence Histopathology Matched tissue diagnoses support outcome verification but cannot substitute for annotations of image-visible evidence. no source asserted
- Concept-based methods usesEvidence Sonographic features Independently annotated sonographic findings can be operationalized as concepts, given validated measurement and separation. no source asserted
- Bayesian inference usesEvidence Clinical history & examination Clinical context supplies information for the prior and likelihood appropriate to the target patient population. Information already included in the prior must not be counted again as independent new evidence in the diagnostic update. no source asserted
- Bayesian decision analysis usesEvidence Clinical history & examination History and examination help specify candidate actions, contraindications and their consequences. A disease posterior becomes an action recommendation only after the clinically relevant consequences are assigned losses. no source asserted
- Reference standard adjudication usesEvidence Histopathology Tissue findings can anchor a diagnostic label only through an explicit correspondence between specimen, lesion, patient and examination time. The same tissue diagnosis does not make its defining morphology visible in every associated image. no source asserted
- Reference standard adjudication usesEvidence Longitudinal follow-up Follow-up can adjudicate later events or disease evolution, but loss of observation before the target horizon is not an automatic negative label. The reference must distinguish censoring, competing events and genuinely observed event-free follow-up. no source asserted
- Reference standard adjudication usesEvidence Clinical history & examination Index-time symptoms and examination findings can form part of a clinical target definition. An image-only surrogate cannot silently replace them when the diagnosis depends on clinical context. no source asserted
- Clinical feature annotation usesEvidence Sonographic features Independent annotation records which features are present, absent, uncertain or unassessable in the available examination. Blinding to model output and, where appropriate, the final diagnosis helps avoid writing the prediction back into its supposed evidence. no source asserted
- Clinical feature annotation usesEvidence Electrophysiological features Annotation can distinguish a waveform event and its time interval from the patient's broader neurological diagnosis. This prevents a patient-level label from being treated as evidence that every sampled window contains a visible event. no source asserted
providesEvidenceFor
EvidenceSource · Finding → ClinicalTarget
Can supply observations bearing on the clinical question, without alone resolving it.
- Ultrasound acquisition providesEvidenceFor Gallbladder disease Adequately acquired ultrasound supplies diagnostically relevant gallbladder observations. doi:10.1007/s13244-017-0544-7
- Sonographic features providesEvidenceFor Gallbladder disease Findings such as intramural cystic spaces support particular differentials; no generic feature establishes every disease. doi:10.1007/s13244-017-0544-7
- Sonographic features providesEvidenceFor Malignancy & staging Scope: malignancy-risk assessment of gallbladder polyps. Morphology and size inform risk, not a pathological stage. doi:10.1007/s00330-021-08384-w
- Histopathology providesEvidenceFor Malignancy & staging Appropriately sampled tissue establishes malignant histology and sampled invasion, not necessarily the complete stage. no source asserted
- Cross-sectional imaging providesEvidenceFor Malignancy & staging CT/MRI supplies evidence about tumour extent and spread, with limits for microscopic disease. doi:10.1259/bjr.20200726
- Cross-sectional imaging providesEvidenceFor Biliary tract Scope: MRCP assessment of ductal configuration, narrowing and filling defects; these do not alone determine cause. no source asserted
- Ultrasound acquisition providesEvidenceFor Liver & hepatobiliary Ultrasound supplies observations of parenchyma and the visible hepatobiliary system, subject to acoustic access. no source asserted
- Cross-sectional imaging providesEvidenceFor Neurological disease Scope: CT/MRI in stroke assessment, including haemorrhage or ischaemic injury; not every neurological diagnosis. doi:10.3174/ajnr.A3690
- Histopathology providesEvidenceFor Gallbladder disease A matched specimen provides tissue-level evidence for the sampled lesion; surgical selection limits generalization. no source asserted
- Clinical history & examination providesEvidenceFor Cardiovascular risk Baseline history and current treatment help define the patient and care setting for a risk estimate. Without their timing, observed risk can be confused with the risk before treatment or with treatment benefit. no source asserted
- Longitudinal follow-up providesEvidenceFor Cardiovascular risk Risk over a specified horizon concerns future events, so later observations supply evidence that a baseline cross-section cannot provide. Censoring and competing events determine which conclusions those observations support. no source asserted
- Duct dilatation providesEvidenceFor Biliary tract The location and extent of enlargement can help localize a biliary problem. They do not by themselves identify the cause, establish active obstruction or determine the presence of infection. no source asserted
- Wall thickening providesEvidenceFor Gallbladder disease Thickness and its pattern bear on the differential diagnosis, but inflammation, benign remodelling and malignancy can overlap. Treating this broad finding as a cancer label discards the clinical alternatives. no source asserted
- Intramural cystic spaces providesEvidenceFor Gallbladder disease Resolved intramural spaces can support a wall-remodelling explanation in the appropriate pattern. Their absence in a limited image is weaker evidence than their confident absence after an adequate examination. no source asserted
- Posterior acoustic effects providesEvidenceFor Gallbladder disease A shadow behind a suspected calculus or comet-tail echoes arising in a wall can change the interpretation of a lesion. An audit that removes all tissue outside the lesion outline may remove precisely this evidence. no source asserted
- Electrophysiological features providesEvidenceFor Neurological disease Electrical discharges can bear on an epilepsy assessment, but a discharge, a recorded clinical event and a diagnosis of recurrent seizure predisposition are different targets. A normal short recording does not universally exclude the disease. no source asserted
- Cross-sectional imaging providesEvidenceFor Acute stroke triage Brain, vascular and tissue imaging can answer different urgent questions about haemorrhage, arterial occlusion and tissue state. The acquisition protocol determines which question an image can support; success on one task does not establish suitability for the others. no source asserted
- Clinical history & examination providesEvidenceFor Gallbladder disease Symptoms and examination findings help distinguish an incidental structural finding from an acute clinical syndrome. An image showing a stone is not by itself a complete reference for diagnosing inflammation or deciding urgency. no source asserted
constrainsProcedure
Standard → Method · Metric
Specifies decision rules or reporting requirements. Compliance is not guaranteed.
- Clinical guidelines constrainsProcedure Diagnostic reasoning Applicable guidelines specify how defined findings and risk factors inform a decision; the example is polyp management. doi:10.1007/s00330-021-08384-w
- Clinical guidelines constrainsProcedure Screening programs A screening guideline supplies eligibility and follow-up rules against which a workflow can be specified and audited. no source asserted
- Reporting standards constrainsProcedure Auditing Scope: diagnostic-accuracy components. STARD specifies reporting of participants, reference procedures and analysis. doi:10.1136/bmj.h5527
- Reporting standards constrainsProcedure Evaluation metrics Reporting requires specified estimates and their precision; compliance does not make a metric appropriate for every claim. doi:10.1136/bmj.h5527
- Reporting standards constrainsProcedure Operating point selection Reporting a threshold-free summary alone leaves the clinically consequential choice of operating point undocumented. doi:10.1371/journal.pone.0118432
warrantsReassessmentOf
Threat → Property · Method
Gives reason to reassess; does not assert that anything has deteriorated.
- Distribution shift warrantsReassessmentOf Calibration Calibration established on one distribution need not persist on another, so reassessment is warranted. arXiv:1906.02530
- Distribution shift warrantsReassessmentOf Uncertainty & abstention Shift motivates checking uncertainty quality and the risk and coverage of any acceptance policy. arXiv:1906.02530
- Distribution shift warrantsReassessmentOf Subgroup & fairness Changed populations or acquisition conditions require reassessing subgroup performance; aggregate results cannot answer it. no source asserted
- Distribution shift warrantsReassessmentOf Robustness A realized shift may or may not fall inside the perturbation family over which robustness was assessed; it warrants checking that coverage rather than establishing that the assessment no longer applies. no source asserted
- Shortcut learning warrantsReassessmentOf Out-of-distribution detection If a site signature is part of what the detector learned to call normal, it can flag a new scanner while passing novel pathology from the familiar one. This is a failure mode to test for, not a guaranteed behaviour. no source asserted
- Deployment feedback loop warrantsReassessmentOf Calibration Once the data reflect the model's own influence, agreement between predictions and recorded outcomes still establishes calibration under that policy and observation process, but no longer under an untreated or differently acted-upon population. no source asserted
- Proxy objective warrantsReassessmentOf Faithfulness A model optimized toward a stand-in has been selected for scoring well on the stand-in; that its reliance matches the target is a question the training never posed. no source asserted
- Proxy objective warrantsReassessmentOf Auditing When the audit's own measure is itself a stand-in for what is being audited, the audit inherits the gap it was meant to detect. no source asserted
- Proxy objective warrantsReassessmentOf Uncertainty & abstention Confidence calibrated against the training objective expresses certainty about the stand-in, which is not certainty about the clinical target. no source asserted
- Outlier influence warrantsReassessmentOf Robustness A fit skewed by a few contaminated records reports an ordinary residual and an ordinary summary; nothing in the output marks the disproportion. no source asserted
- Shortcut learning warrantsReassessmentOf Ensembling Members sharing an architecture, a training set and a preprocessing pipeline share the biases those impose, so a shortcut present in the data can leave them agreeing confidently and wrong together. Agreement is therefore weak evidence of correctness under a shared shortcut. no source asserted
- Label noise warrantsReassessmentOf Auditing When the reference standard is itself several points from correct, disagreement between model and standard no longer separates model error from annotation error. arXiv:2006.07159
- Label noise warrantsReassessmentOf Calibration Probabilities fitted to agree with noisy labels are calibrated to the annotation process, and the agreement is evidence about that process rather than about the condition. arXiv:2006.07159
- Deployment feedback loop warrantsReassessmentOf Stability margin A path from a model's outputs back into its own training data is a feedback path, so a margin measured on the open pipeline need not bound the deployed one. The control reading holds only where the dynamics, delays and update rule are made explicit; a learning loop does not automatically possess a defined gain margin. no source asserted
- Selection & verification bias warrantsReassessmentOf Pretest probability Prevalence among verified or referred cases need not equal prevalence among consecutive intended-use patients. The selection mechanism must be examined before using that frequency as a clinical prior. no source asserted
- Selection & verification bias warrantsReassessmentOf Clinical validity Accuracy conditional on receiving a reference examination is not automatically accuracy in the target population. Differential verification or missing outcomes can change which errors are observable. no source asserted
- Distribution shift warrantsReassessmentOf Pretest probability A change in referral or recruitment may alter baseline disease odds. Retaining the development prior requires evidence about the new clinical population, rather than an assumption that all shifts leave prevalence unchanged. no source asserted
- Deployment feedback loop warrantsReassessmentOf Transportability If deployment changes who is tested, treated or labelled, the future data-generating process can depend on the policy itself. Validation under the previous care policy does not by itself cover the resulting feedback regime. no source asserted
doesNotEstablish
Property · Method · Metric · EvidenceSource · Standard → Property · Finding
The subject alone is insufficient to establish the object. Non-entailment, not incompatibility.
- Plausibility doesNotEstablish Faithfulness A visually convincing explanation can be insensitive to learned parameters, so reasonableness does not entail faithfulness. arXiv:1810.03292
- Faithfulness doesNotEstablish Plausibility A faithful explanation of caliper reliance accurately describes an inappropriate rule without making it clinically plausible. no source asserted
- Calibration doesNotEstablish Faithfulness Agreement between probabilities and outcome frequencies does not constrain whether an explanation describes the predictor. no source asserted
- Evaluation metrics doesNotEstablish Faithfulness Scope: predictive-performance metrics such as AUROC. They describe predictions against labels, not the computation. no source asserted
- Segmentation & detection doesNotEstablish Faithfulness Localization or mask overlap does not establish that an explanation identifies the evidence a diagnostic predictor used. no source asserted
- Histopathology doesNotEstablish Sonographic features A tissue diagnosis does not establish that a finding was visible or assessable in the frame supplied to the model. no source asserted
- Reporting standards doesNotEstablish Faithfulness A compliant report can describe a method whose faithfulness claim remains unsupported. no source asserted
- Evaluation metrics doesNotEstablish Robustness A score on a held-out sample from one distribution quantifies performance on that distribution and asserts nothing about behaviour under shift. no source asserted
- Robustness doesNotEstablish Faithfulness Stability under perturbation of the learned representation is compatible with that representation encoding a shortcut; a wide margin around the wrong feature is still a wide margin. no source asserted
- Evaluation metrics doesNotEstablish Plausibility A performance figure quantifies agreement with labels and carries no claim about whether the model's reasoning would be recognized as sensible. no source asserted
- Out-of-distribution detection doesNotEstablish Robustness Declining to answer on inputs judged unfamiliar is not evidence of correct behaviour on inputs judged familiar. no source asserted
- Hypothesis testing doesNotEstablish Robustness A p-value is conditional on the null being true and supplies no probability that any hypothesis holds, let alone that performance transports. doi:10.1080/00031305.2016.1154108
- Translation invariance doesNotEstablish Faithfulness A representation trained to be unchanged by position has been rewarded for discarding the spatial correspondence that an attribution map asserts. no source asserted
- Attention mechanism doesNotEstablish Faithfulness An attention weight reports how much a value vector was routed into an update; by the second layer that vector already summarizes much of the sequence, so the weight is a routing diagram and not an attribution. arXiv:1706.03762
- Ensembling doesNotEstablish Calibration Spread across independently initialized models supplies a predictive distribution where a point estimate supplies only a score, but the spread is a property of the ensemble, not a comparison with observed outcomes. Calibration assessment requires that comparison. arXiv:1612.01474
- Evaluation metrics doesNotEstablish Stability margin A point estimate on a fixed test set reports current performance; it says nothing about how far inputs or thresholds can move before that performance fails. no source asserted
- Operating point selection doesNotEstablish Stability margin Choosing a threshold fixes an operating point without quantifying how much the score distribution may shift before the choice stops holding. no source asserted
- Causal identifiability doesNotEstablish Clinical utility Identifying a treatment effect does not establish that a learned decision rule improves care: the policy, patient population, competing consequences and implementation still need assessment. no source asserted
- Simulation-based policy evaluation doesNotEstablish Clinical utility A favourable simulated return is conditional on the state, action, reward and transition model. It is not an observed improvement in patient outcomes, and a reward can omit harms that matter clinically. no source asserted
- Constrained optimization doesNotEstablish Clinical validity Even a certified global optimum only solves the stated objective over the stated feasible set; it cannot repair a mismatched clinical target, an invalid reference label or a constraint that encodes the wrong requirement. no source asserted
- Measurement identifiability doesNotEstablish Clinical assessability A unique solution in a noiseless model can remain too sensitive to noise or finite resolution to support a finding in the actual examination. Uniqueness and usable measurement precision are different requirements. no source asserted
- Evaluation metrics doesNotEstablish Inverse-problem conditioning Error on a fixed test set does not report how much a reconstructed quantity can change under measurement perturbations; that requires a forward model, perturbation scale and sensitivity assessment. no source asserted
- Inverse reconstruction doesNotEstablish Sonographic features A structure present in a reconstructed image may be supplied by the reconstruction prior rather than resolved by the acquired echoes. Its appearance alone does not establish that the corresponding finding was measured in this patient. no source asserted
- Stability margin doesNotEstablish Clinical utility A loop can remain stable while regulating the wrong quantity or pursuing a clinically harmful target. Distance from an instability boundary does not establish benefit from the action being stabilized. no source asserted
- Bayesian inference doesNotEstablish Calibration A posterior is conditional on its probability model and prior; those choices can be wrong for the deployment population. Calling an output Bayesian does not replace checking agreement between its probabilities and observed outcomes. no source asserted
- Faithfulness doesNotEstablish Clinical evidence reliance An explanation can accurately report that the model used a site marker or another shortcut. Correctly describing the computation does not make its evidence clinically appropriate. no source asserted
- Clinical validity doesNotEstablish Clinical utility An output can correspond accurately to the intended clinical condition without improving decisions or patient outcomes. Clinical benefit additionally depends on what users do with it and on the consequences compared with usual care. no source asserted
- Hypothesis testing doesNotEstablish Clinical validity Rejecting a statistical null under the sampling model cannot repair a wrong target, a biased reference process or an incorrect unit of analysis. Statistical significance does not turn those observations into evidence for the intended clinical claim. no source asserted
- Internal validation doesNotEstablish Transportability An independent split can still share acquisition, referral, treatment and labelling mechanisms with development. Independence of held-out patients does not test whether the model's behaviour persists when those mechanisms change. no source asserted
- External validation doesNotEstablish Clinical evidence reliance A shortcut can persist across institutions, so successful external prediction does not identify which evidence the model used. Testing transport and testing clinical reliance answer different questions. no source asserted
- External validation doesNotEstablish Clinical utility Retrospective performance on another site's cases does not show how clinicians act on the output or whether outcomes improve. Those consequences require assessment of the intended use within care. no source asserted
- Clinical validity doesNotEstablish Clinical evidence reliance Agreement with a valid clinical target can coexist with reliance on a correlated care-process cue. A correct diagnosis and a correct account of which clinical evidence produced it are separate claims. no source asserted
- Representation learning doesNotEstablish Transportability A descriptor fitted as a free per-case vector has no rule mapping a new case's observations to a vector, so nothing in the fitted table applies to a case absent at training time. Optimizing an appended row afterwards is additional fitting, not inference through the trained model. no source asserted
canAudit
Method → Method · ModelFamily · EvidenceSource
Instances or outputs of the object can be explicit inspection targets of the subject.
- Auditing canAudit Foundation models An adapted instance can be frozen and audited for its evidence use; pretraining scale is not an exemption. no source asserted
- Auditing canAudit Representation learning Representations can be inspected for encoded clinical and acquisition information, keeping decodability separate from reliance. no source asserted
- Auditing canAudit Segmentation & detection Segmentation outputs can be audited for dependence on documentation cues. doi:10.1007/978-3-031-72111-3_59
- Auditing canAudit Attribution & saliency Parameter and label randomization test whether attribution outputs respond to the learned predictor at all. arXiv:1810.03292
- Auditing canAudit Concept-based methods Audit the concept examples, held-out measurement quality, correlated concepts and claimed sensitivity. no source asserted
- Auditing canAudit Counterfactual Inspect whether an edited comparison changes its intended target while preserving other evidence. no source asserted
- Exploration & stress testing canAudit Foundation models Stress conditions can be applied to a fixed model's outputs without access to its training data. no source asserted
- Subgroup & fairness canAudit Similarity & graph construction Degree normalization decides how far the densely connected majority sets the geometry, so the graph construction is itself a legitimate target of subgroup analysis. no source asserted
- Auditing canAudit Preprocessing & resampling The pipeline that produced the inputs is itself an inspection target, and one that attribution over image content cannot reach. no source asserted
- Operating point selection canAudit Subgroup & fairness One threshold applied across groups of differing prevalence produces different error profiles per group; sweeping it exposes that dependence. doi:10.1145/3287560.3287598
- Auditing canAudit Post-processing The steps between a network's output and the reported result are a separate inspection target; a fault there is invisible to any method examining only the model. no source asserted
- Auditing canAudit Objective design Loss choice and per-sample weighting are where class priorities are actually encoded; reading them is more direct than inferring priorities from performance. no source asserted
- Auditing canAudit Pseudo-labelling The labelling model is an inspection target in its own right, and one that evaluating the final model against those same labels cannot reach. no source asserted
changesObservabilityOf
EvidenceSource · Method → Finding
Can change the visibility or assessability of findings without a change in underlying disease.
- Ultrasound acquisition changesObservabilityOf Sonographic features Acquisition modes alter acoustic findings; spatial compounding changed shadow appearance in a stone phantom. doi:10.1148/rg.2017160175
- Intervention & ablation changesObservabilityOf Sonographic features Masking can erase diagnostically relevant morphology as well as the suspected nuisance cue. no source asserted
- Preprocessing & resampling changesObservabilityOf Sonographic features Interpolation and filtering can suppress fine texture that a reader or model would otherwise assess. no source asserted
- Post-processing changesObservabilityOf Sonographic features Overlap-based suppression deletes true detections lying closer than its threshold, after the model has already scored them. doi:10.1109/TPAMI.2016.2577031
- Implicit representation changesObservabilityOf Sonographic features A field queried between its training views renders interpolated structure with the same appearance as measured structure, and the output carries no marker separating them. doi:10.1007/978-3-030-58452-8_24
- Ultrasound acquisition changesObservabilityOf Duct dilatation Duct calibre must be assessed in an adequately visualized segment and plane. Obscuration or incomplete coverage can make a normal-looking frame uninformative about the rest of the biliary tree. no source asserted
- Ultrasound acquisition changesObservabilityOf Intramural cystic spaces Depth, focus, resolution and the chosen plane affect whether small intramural spaces can be resolved. A change in their visibility across images need not indicate a change in the wall's underlying structure. no source asserted
- Ultrasound acquisition changesObservabilityOf Posterior acoustic effects Beam angle and compounding can change the appearance of shadows and reverberation. Their stability under an image transformation cannot be assumed merely because the biological lesion is unchanged. no source asserted
- Preprocessing & resampling changesObservabilityOf Intramural cystic spaces Reducing spatial resolution can remove a small resolved cavity while preserving the overall thickened-wall outline. Preserving the coarse diagnostic label therefore does not guarantee preservation of the evidence used to justify it. no source asserted
- Electrophysiological recording changesObservabilityOf Electrophysiological features Electrode placement, montage, filtering and recording duration affect which electrical phenomena can be observed. Failure to capture an intermittent event is a limit of the observation as well as a possible clinical negative. no source asserted
limitsClaim
Principle · Property → Method · Metric · Property
Constrains what can be inferred or jointly guaranteed under the assumptions named in the assertion; does not assert an empirical failure.
- Identifiability criterion limitsClaim Causal inference If two causal models satisfy the stated assumptions and generate the same observational distribution but disagree on the target effect, that effect is not identified; more observations from that same distribution cannot resolve the disagreement. no source asserted
- Identifiability criterion limitsClaim Counterfactual An identified interventional distribution need not identify an individual counterfactual. Changing pixels tests a computational input intervention; interpreting the result as what would have happened to the patient requires an additional causal argument. no source asserted
- Identifiability criterion limitsClaim Simulation-based policy evaluation Dynamics can agree on every observed action yet disagree on actions absent from the records. A simulator chooses among those possibilities through assumptions; agreement with retrospective trajectories alone does not identify the value of an unsupported policy. no source asserted
- Sampling theorem limitsClaim Measurement identifiability For a signal band-limited to B, ideal noiseless uniform sampling above 2B permits reconstruction. If the admissible signal class instead contains aliases, distinct continuous signals can produce the same samples and the original is not uniquely determined. no source asserted
- Sampling theorem limitsClaim Preprocessing & resampling Before decimation, frequencies outside the new representable band must be removed if aliasing is to be excluded for arbitrary inputs. Upsampling after folding has occurred cannot determine which original frequency produced a sampled component. no source asserted
- Data processing inequality limitsClaim Representation learning For a fixed encoder whose only patient-specific input is the image, processing cannot increase mutual information with disease relative to that input. It can make existing information easier for a chosen decoder to use; dependence still does not establish causal relevance. no source asserted
- Data processing inequality limitsClaim Inverse reconstruction With a fixed reconstruction model and no additional patient measurements, a prior can select or average among compatible images but cannot add patient-specific information absent from the input. A plausible reconstruction is therefore not a new observation. no source asserted
- Feedback sensitivity identity limitsClaim Feedback correction For the scalar negative-feedback loop S = 1/(1+L) and T = L/(1+L), S+T=1 and hence |S|+|T|>=1 wherever defined. Suppressing output-disturbance transmission through S leaves sensor-noise transmission through T near unity; this is not a theorem about arbitrary clinical learning loops. no source asserted
- Bias-variance decomposition limitsClaim Evaluation metrics Under squared loss with conditionally zero-mean test noise independent of training, expected prediction error decomposes into squared bias, estimator variance and irreducible noise. A single test score does not identify those terms, and the identity does not impose a conserved budget preventing bias and variance from both improving. no source asserted
- Bayes error bound limitsClaim Operating point selection With nonzero class priors and overlapping class-conditional distributions on a set of positive probability, the fixed measurements imply positive Bayes classification error. A threshold cannot make both false positives and false negatives vanish; precision and recall nevertheless have no universal conserved sum, and better measurements can change the bound. no source asserted
- Pretest probability limitsClaim Predictive values Bayes' rule gives PPV = Se*pi/(Se*pi + (1-Sp)*(1-pi)) for sensitivity Se, specificity Sp and prevalence pi. Transferring a positive predictive value therefore requires the target prevalence and justification that the conditional test characteristics also transfer. no source asserted
- Clinical assessability limitsClaim Clinical evidence reliance When the acquisition cannot resolve a specified finding, agreement with a patient diagnosis cannot establish reliance on that finding in this image. Prediction may instead depend on other measured evidence or on prior information; human difficulty alone is not proof of physical non-observability. no source asserted
- Data processing inequality limitsClaim Similarity & graph construction Each message-passing layer is a function of the previous layer's states, so a node descriptor can carry no information about a relation that the edge rule did not already supply. Repeated neighbourhood averaging contracts the differences it does not preserve; adding depth cannot recover them. no source asserted
setsRequirementsFor
ClinicalTarget → Method · Metric
The clinical question determines which target, unit, timing, evidence, or consequence the procedure or metric must address.
- Gallbladder disease setsRequirementsFor Intended use specification Detecting a stone, diagnosing acute inflammation and characterizing possible malignancy are different questions. Each requires its own target, unit of analysis, available inputs and intended clinical action before a performance claim has a determinate meaning. no source asserted
- Malignancy & staging setsRequirementsFor Reference standard adjudication A specimen-level cancer diagnosis must be matched to the imaged lesion and relevant examination time. Patient-level staging cannot simply become a positive label for every image frame. no source asserted
- Cardiovascular risk setsRequirementsFor Reference standard adjudication A prognostic label needs a baseline, prediction horizon and outcome definition, with explicit treatment of censoring and competing events. Outcomes observed under treatment do not directly label the patient's untreated risk. no source asserted
- Acute stroke triage setsRequirementsFor Evaluation metrics A triage claim must account for which urgent cases are missed, which alerts consume attention and when a result changes action. Ranking accuracy or isolated inference time does not measure the full clinical delay. no source asserted
- Neurological disease setsRequirementsFor Clinical feature annotation A visible movement, an electrical discharge and a longitudinal neurological diagnosis are different annotation targets. The protocol must state the observation interval and relevant clinical state rather than treating an unrecorded phenomenon as absent. no source asserted
- Gallbladder disease setsRequirementsFor Intervention & ablation For an audit of stone or wall-lesion evidence, preserving the lesion outline is insufficient if the edit destroys posterior shadowing or intramural detail. Clinical interpretation determines which surrounding signal must remain controlled. no source asserted
- Acute stroke triage setsRequirementsFor Comparative workflow evaluation A claim of faster clinically useful triage requires measuring the path from acquisition to review and action, including alert burden and downstream delays. Faster computation alone cannot establish a shorter treatment pathway. no source asserted
- Cardiovascular risk setsRequirementsFor Bayesian decision analysis Choosing prevention requires expected benefits and harms of an action, not only the probability of an event under observed care. A risk predictor must not be silently reinterpreted as an estimate of treatment effect. no source asserted
canManifestAs
Mechanism → Finding
Can generate the finding under specified biological or measurement conditions; neither necessary presence nor diagnostic specificity is implied.
- Biliary obstruction canManifestAs Duct dilatation Impaired bile outflow can produce upstream duct enlargement, but its visibility depends on timing and context. Dilatation can persist after obstruction is relieved, and a nondilated duct does not universally exclude obstruction. no source asserted
- Inflammatory change canManifestAs Wall thickening Inflammation can produce gallbladder wall oedema and thickening. The morphology is not specific to inflammation, so the same measurement needs clinical context and competing explanations. no source asserted
- Neoplastic invasion canManifestAs Wall thickening An infiltrating gallbladder malignancy can present as wall thickening rather than a discrete mass. Because benign processes can produce the same broad finding, detecting thickness alone does not identify malignant invasion. no source asserted
- Benign wall remodelling canManifestAs Intramural cystic spaces In gallbladder adenomyomatosis, wall remodelling can include intramural sinus spaces that appear cystic when resolved. This provides a benign structural explanation to consider rather than treating every thickened wall as malignancy. no source asserted
- Acoustic propagation canManifestAs Posterior acoustic effects Reflection, reverberation and attenuation along the beam path can produce posterior shadows or comet-tail echoes. Such appearances arise from tissue interacting with acquisition and can carry diagnostic information rather than being disposable nuisance texture. no source asserted
- Neuronal network activity canManifestAs Electrophysiological features Electrical activity can generate recordable field patterns, but the measured waveform depends on spatial summation, source orientation and recording conditions. Disease need not produce a diagnostic event during the available recording interval. no source asserted
Absence of an edge means not asserted, not false. doesNotEstablish is itself a positive claim of non-entailment, not a claim of incompatibility. None of this determines whether a particular trained model uses a shortcut; that needs an experiment.