Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Syed, Tahir Qasim, Khan, Behraj
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:https://arxiv.org/abs/2602.02633
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866908807825719296
author Syed, Tahir Qasim
Khan, Behraj
author_facet Syed, Tahir Qasim
Khan, Behraj
contents Often, constraints arise in deployment settings where even lightweight parameter updates e.g. parameter-efficient fine-tuning could induce model shift or tuning instability. We study test-time adaptation of foundation models for few-shot classification under a completely frozen-model regime, where additionally, no upstream data are accessible. We propose arguably the first training-free inference method that adapts predictions to the new task by performing a change of measure over the latent embedding distribution induced by the encoder. Using task-similarity scores derived from a small labeled support set, exponential tilting reweights latent distributions in a KL-optimal manner without modifying model parameters. Empirically, the method consistently competes with parameter-update-based methods across multiple benchmarks and shot regimes, while operating under strictly and universally stronger constraints. These results demonstrate the viability of inference-level distributional correction for test-time adaptation even with a fully-frozen model pipeline.
format Preprint
id arxiv_https___arxiv_org_abs_2602_02633
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Rethinking Test-Time Training: Tilting The Latent Distribution For Few-Shot Source-Free Adaptation
Syed, Tahir Qasim
Khan, Behraj
Machine Learning
Often, constraints arise in deployment settings where even lightweight parameter updates e.g. parameter-efficient fine-tuning could induce model shift or tuning instability. We study test-time adaptation of foundation models for few-shot classification under a completely frozen-model regime, where additionally, no upstream data are accessible. We propose arguably the first training-free inference method that adapts predictions to the new task by performing a change of measure over the latent embedding distribution induced by the encoder. Using task-similarity scores derived from a small labeled support set, exponential tilting reweights latent distributions in a KL-optimal manner without modifying model parameters. Empirically, the method consistently competes with parameter-update-based methods across multiple benchmarks and shot regimes, while operating under strictly and universally stronger constraints. These results demonstrate the viability of inference-level distributional correction for test-time adaptation even with a fully-frozen model pipeline.
title Rethinking Test-Time Training: Tilting The Latent Distribution For Few-Shot Source-Free Adaptation
topic Machine Learning
url https://arxiv.org/abs/2602.02633