Graph Out-of-Distribution Detection via Test-Time Calibration with Dual Dynamic Dictionaries

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Hou, Yue, Liu, Ruomei, Su, Yingke, Wu, Junran, Xu, Ke
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866912725957869568
author Hou, Yue
Liu, Ruomei
Su, Yingke
Wu, Junran
Xu, Ke
author_facet Hou, Yue
Liu, Ruomei
Su, Yingke
Wu, Junran
Xu, Ke
contents A key challenge in graph out-of-distribution (OOD) detection lies in the absence of ground-truth OOD samples during training. Existing methods are typically optimized to capture features within the in-distribution (ID) data and calculate OOD scores, which often limits pre-trained models from representing distributional boundaries, leading to unreliable OOD detection. Moreover, the latent structure of graph data is often governed by multiple underlying factors, which remains less explored. To address these challenges, we propose a novel test-time graph OOD detection method, termed BaCa, that calibrates OOD scores using dual dynamically updated dictionaries without requiring fine-tuning the pre-trained model. Specifically, BaCa estimates graphons and applies a mix-up strategy solely with test samples to generate diverse boundary-aware discriminative topologies, eliminating the need for exposing auxiliary datasets as outliers. We construct dual dynamic dictionaries via priority queues and attention mechanisms to adaptively capture latent ID and OOD representations, which are then utilized for boundary-aware OOD score calibration. To the best of our knowledge, extensive experiments on real-world datasets show that BaCa significantly outperforms existing state-of-the-art methods in OOD detection.
format Preprint
id arxiv_https___arxiv_org_abs_2511_13541
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Graph Out-of-Distribution Detection via Test-Time Calibration with Dual Dynamic Dictionaries
Hou, Yue
Liu, Ruomei
Su, Yingke
Wu, Junran
Xu, Ke
Machine Learning
A key challenge in graph out-of-distribution (OOD) detection lies in the absence of ground-truth OOD samples during training. Existing methods are typically optimized to capture features within the in-distribution (ID) data and calculate OOD scores, which often limits pre-trained models from representing distributional boundaries, leading to unreliable OOD detection. Moreover, the latent structure of graph data is often governed by multiple underlying factors, which remains less explored. To address these challenges, we propose a novel test-time graph OOD detection method, termed BaCa, that calibrates OOD scores using dual dynamically updated dictionaries without requiring fine-tuning the pre-trained model. Specifically, BaCa estimates graphons and applies a mix-up strategy solely with test samples to generate diverse boundary-aware discriminative topologies, eliminating the need for exposing auxiliary datasets as outliers. We construct dual dynamic dictionaries via priority queues and attention mechanisms to adaptively capture latent ID and OOD representations, which are then utilized for boundary-aware OOD score calibration. To the best of our knowledge, extensive experiments on real-world datasets show that BaCa significantly outperforms existing state-of-the-art methods in OOD detection.
title Graph Out-of-Distribution Detection via Test-Time Calibration with Dual Dynamic Dictionaries
topic Machine Learning
url https://arxiv.org/abs/2511.13541