Distribution-free changepoint localization after sequential change detection
- URL: http://arxiv.org/abs/2606.01256v1
- Date: Sun, 31 May 2026 14:18:41 GMT
- Title: Distribution-free changepoint localization after sequential change detection
- Abstract summary: This paper introduces a distribution-free framework for constructing post-detection confidence sets for changepoints.<n>It is the first general distribution-free framework for sequential changepoint localization with a valid post-detection coverage guarantee.
- Score: 36.83591711369991
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: This paper introduces a distribution-free framework for constructing post-detection confidence sets for changepoints after stopping a sequential change detection procedure. It is well known that conformal test martingales can be used to sequentially detect changes in distribution, but by themselves provide no inference for the time at which a proclaimed change occurred. Past work on post-detection inference requires pre- and post-change classes of distributions to be known, but this paper accomplishes localization of the changepoint without any distributional assumptions. We establish finite-sample coverage guarantees (conditional on correct detection). We provide non-asymptotic bounds on the conditional expected size of the confidence sets. Under suitable asymptotic regimes, we proved that the conditional expected size of the confidence set remains uniformly bounded. and demonstrate strong empirical performance on simulated and real data. To the best of our knowledge, this is the first general distribution-free framework for sequential changepoint localization with a valid post-detection coverage guarantee.
Related papers
- Robust Conditional Conformal Prediction via Branched Normalizing Flow [20.92399096303012]
Conformal prediction constructs with marginal coverage guarantees under the assumption that the calibration and test distributions are identical.<n>We introduce Branched Normalizing Flow (BNF), a two-branch architecture that normalizes a test input to the calibration distribution and transforms the prediction set of the normalized input back to the test distribution.<n>BNF consistently improves conditional coverage robustness on nine datasets across a wide range of confidence levels.
arXiv Detail & Related papers (2026-05-03T13:29:26Z) - Coverage Guarantees for Pseudo-Calibrated Conformal Prediction under Distribution Shift [1.5861469511290378]
Conformal prediction offers marginal coverage guarantees if the data distribution shifts.<n>We analyze the use of pseudo-calibration as a tool to counter this performance loss.<n>We propose a source-tuned pseudo-calibration algorithm that interpolates between hard pseudo-labels and randomized labels.
arXiv Detail & Related papers (2026-02-16T16:48:39Z) - Conformal changepoint localization [36.191356601153146]
We study the problem of offline changepoint localization in a distribution-free setting.<n>We produce a finite-sample confidence set for the index at which the change occurs without making any other assumptions.<n>Experiments suggest that CONCH delivers precise confidence sets even in challenging settings involving images or text.
arXiv Detail & Related papers (2026-02-05T23:50:53Z) - Theoretical guarantees for change localization using conformal p-values [36.191356601153146]
We provide theoretical guarantees for a method to achieve distribution-free changepoint localization with finite-sample validity.<n>We also present various finite sample and properties of the conformal $p$-value in the distribution change setup.<n>Our contributions offer a comprehensive and theoretically principled approach to distribution-free changepoint inference.
arXiv Detail & Related papers (2025-10-09T19:05:47Z) - Rectifying Conformity Scores for Better Conditional Coverage [75.73184036344908]
We present a new method for generating confidence sets within the split conformal prediction framework.<n>Our method performs a trainable transformation of any given conformity score to improve conditional coverage while ensuring exact marginal coverage.
arXiv Detail & Related papers (2025-02-22T19:54:14Z) - Post-detection inference for sequential changepoint localization [29.43493007296859]
We develop a framework to construct confidence sets for the unknown changepoint using only the data observed up to a data-dependent stopping time at which an arbitrary sequential detection algorithm declares a change.<n>Our framework is nonparametric, making no assumption on the composite post-change class, the observation space, or the sequential detection procedure used, and is nonasymptotically valid.
arXiv Detail & Related papers (2025-02-10T02:01:30Z) - When Does Confidence-Based Cascade Deferral Suffice? [69.28314307469381]
Cascades are a classical strategy to enable inference cost to vary adaptively across samples.
A deferral rule determines whether to invoke the next classifier in the sequence, or to terminate prediction.
Despite being oblivious to the structure of the cascade, confidence-based deferral often works remarkably well in practice.
arXiv Detail & Related papers (2023-07-06T04:13:57Z) - Distribution-free uncertainty quantification for classification under
label shift [105.27463615756733]
We focus on uncertainty quantification (UQ) for classification problems via two avenues.
We first argue that label shift hurts UQ, by showing degradation in coverage and calibration.
We examine these techniques theoretically in a distribution-free framework and demonstrate their excellent practical performance.
arXiv Detail & Related papers (2021-03-04T20:51:03Z) - Distribution-free binary classification: prediction sets, confidence
intervals and calibration [106.50279469344937]
We study three notions of uncertainty quantification -- calibration, confidence intervals and prediction sets -- for binary classification in the distribution-free setting.
We derive confidence intervals for binned probabilities for both fixed-width and uniform-mass binning.
As a consequence of our 'tripod' theorems, these confidence intervals for binned probabilities lead to distribution-free calibration.
arXiv Detail & Related papers (2020-06-18T14:17:29Z) - Optimal Change-Point Detection with Training Sequences in the Large and
Moderate Deviations Regimes [72.68201611113673]
This paper investigates a novel offline change-point detection problem from an information-theoretic perspective.
We assume that the knowledge of the underlying pre- and post-change distributions are not known and can only be learned from the training sequences which are available.
arXiv Detail & Related papers (2020-03-13T23:39:40Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.