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Under Review · Applied Intelligence

TrustShift

One pre-registered audit across four dissimilar domains: the type of distribution shift — not its magnitude — determines which axis of trustworthiness fails at deployment.

Rajveer Singh Pall · 2026

ProblemML systems are audited domain by domain, and deployment failures are usually blamed on how large the distribution shift is. Whether the kind of shift predicts the kind of failure had never been tested across domains under one protocol.
ApproachOne pre-registered audit applied to clinical risk, mental-health NLP, mortgage lending, and network security — discrimination, calibration, and subgroup reliability measured under each deployment shift, then explained by three cheap label-free probes.
ResultShift type, not shift magnitude, predicts which trustworthiness axis degrades — and the responsible shift type is diagnosable in advance from unlabeled data.
SignificancePost-hoc deployment surprises become a pre-deployment diagnostic: the auditor can anticipate the failure axis before labels arrive, and match the repair to the diagnosis.

The Discovery in One Figure

SHIFT TYPE → FAILURE AXIS (NOT SHIFT MAGNITUDE) LABEL SHIFT COVARIATE SHIFT CONCEPT SHIFT 3 LABEL-FREE PROBES DIAGNOSE THE TYPE IN ADVANCE CALIBRATION FAILS SUBGROUPS FAIL DISCRIMINATION FAILS CLINICAL RISK · MENTAL-HEALTH NLP · MORTGAGE LENDING · NETWORK SECURITY — ONE PRE-REGISTERED PROTOCOL

The kind of change in the world — not the amount of change — decides what breaks.

The Paper in Five Minutes

A machine-learning model is trained on yesterday's data and then released into a world that keeps changing. Everyone knows performance can drop — but not all drops are alike. Sometimes the model still ranks people correctly but its probability estimates become dishonest; sometimes it fails one demographic group; sometimes it collapses entirely. This paper studies four completely different fields at once — medicine, social-media language, mortgage lending, and network attacks — under one identical audit, and finds that the kind of change in the world, not the amount of change, decides what breaks. Better still, the kind is detectable in advance, from unlabeled data, so the right repair can be chosen before anyone is harmed.

The Research Question

ML systems are audited domain by domain, and deployment failures are usually attributed to how large the distribution shift is. Whether the kind of shift predicts the kind of failure had not been tested across domains under one protocol.

How It Works

A single pre-registered audit protocol applied to four real-world domains — clinical risk (NHANES→BRFSS), mental-health NLP (Kaggle→Reddit/Twitter), mortgage lending (42M HMDA applications), and network security (CIC-DDoS2019→CICIDS2017). Discrimination, calibration, and subgroup reliability are measured with DeLong and bootstrap confidence intervals (N = 2000) and Benjamini–Hochberg FDR control, then explained by three cheap, label-free shift probes: prevalence shift, domain-classifier AUC, and importance-reweighting residual.

01
Deployment shiftone trained model per domain meets a changed population
02
Three label-free probesprevalence shift · domain-classifier AUC · reweighting residual
03
Shift-type diagnosislabel, covariate, or concept shift — before outcomes arrive
04
Failure taxonomywhich axis breaks: discrimination, calibration, or subgroups
05
Matched remediationrecalibrate · reweight · retrain — chosen by diagnosis

The Results

4Domains, one protocol
3Label-free shift probes
N=2000Bootstrap CIs · BH-FDR
exit 0Byte-identical re-run

Shift type, not shift magnitude, predicts which trustworthiness axis degrades — and the responsible shift type is diagnosable in advance from unlabeled data, mapping each diagnosis to the appropriate remediation: recalibration, reweighting, or retraining. The full pipeline re-runs from a fresh clone to byte-identical result tables.

The audit, domain by domain: discrimination, calibration, and subgroup reliability under each deployment shift
The audit, domain by domain: discrimination, calibration, and subgroup reliability measured under each deployment shift.
Deployment damage organised by shift type rather than shift magnitude
The headline result: deployment damage organised by shift type rather than shift magnitude across the shift points.
The remediation ladder across domains
The remediation ladder: label-cheap recalibration repairs calibration everywhere; discrimination requires more.

What This Changes

It converts post-hoc deployment surprises into a pre-deployment diagnostic: an auditor can anticipate the failure axis before labels arrive. And it binds the program's clinical, NLP, lending, and security evidence into one reproducible benchmark — the thesis that holds the rest of this research together.

↗ View on GitHub ↗ Dataset on Hugging Face ↗ Full research page

Citation

Rajveer Singh Pall. "TrustShift: Shift Type, Not Shift Magnitude, Determines Machine-Learning Failure Modes." Under review, Applied Intelligence, 2026.

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