Abstract

Worst-group accuracy (WGA) evaluates a trained predictor but does not characterize how its frozen backbone behaves when a new head is learned. We introduce BiasFlow, a hook-based toolkit for monitoring class-attribute centroid alignment (IBMI), within-class centroid separation (W-IBMI), and feature-projection sensitivity. IBMI is confounded by class-attribute correlation and is not a measure of causal feature reliance. We pair these diagnostics with BiasFlow Regularization (BFR), a supervised, composable class-conditional centroid-alignment penalty. W-IBMI verifies the quantity BFR optimizes; it is scale dependent and does not independently establish attribute removal. Across the reported small-scale benchmarks, adding BFR improves or preserves mean WGA, with gains up to +26.0 pp on UrbanCars. The principal independent stress test freezes CelebA-Std backbones and trains fresh heads on biased data: BFR+GroupDRO improves WGA from 40.7% to 64.1%, while Male probe accuracy decreases from 92.5% to 72.2%. Attribute information remains recoverable, and cross-task results are mixed. A controlled synthetic-watermark ImageNet experiment additionally improves watermark-shift accuracy by +23.0 pp under matched training. These results support evaluating centroid geometry and resistance to biased head retraining alongside WGA, within the tested protocols.

Keywords

Subject

Publication details

Journal
Not available
Open access
Green open access

Cite this article

APA 7

Deng, H., Lin, Z., & Yang, Y. (2026). BiasFlow: Geometric Monitoring and Backbone Regularization for Spurious Feature Reliance. https://omanscience.com/en/articles/biasflow-geometric-monitoring-and-backbone-regularization-for-spurious-feature-reliance

MLA 9

Deng, Haojin, et al. "BiasFlow: Geometric Monitoring and Backbone Regularization for Spurious Feature Reliance." https://omanscience.com/en/articles/biasflow-geometric-monitoring-and-backbone-regularization-for-spurious-feature-reliance.

Chicago (author–date)

Deng, Haojin, Zhiping Lin, and Yimin Yang. 2026. "BiasFlow: Geometric Monitoring and Backbone Regularization for Spurious Feature Reliance." https://omanscience.com/en/articles/biasflow-geometric-monitoring-and-backbone-regularization-for-spurious-feature-reliance.

Harvard

Deng, H., Lin, Z. and Yang, Y. (2026) 'BiasFlow: Geometric Monitoring and Backbone Regularization for Spurious Feature Reliance', Available at: https://omanscience.com/en/articles/biasflow-geometric-monitoring-and-backbone-regularization-for-spurious-feature-reliance.

Vancouver

Deng H, Lin Z, Yang Y. BiasFlow: Geometric Monitoring and Backbone Regularization for Spurious Feature Reliance. https://omanscience.com/en/articles/biasflow-geometric-monitoring-and-backbone-regularization-for-spurious-feature-reliance

IEEE

H. Deng, Z. Lin, and Y. Yang, "BiasFlow: Geometric Monitoring and Backbone Regularization for Spurious Feature Reliance," https://omanscience.com/en/articles/biasflow-geometric-monitoring-and-backbone-regularization-for-spurious-feature-reliance.