arXiv Machine Learning

Replication Failure and Trivial Baselines in Road-Level Crash Prediction

arXiv Machine Learning
Sep 11

When does a spectral prior help graph learning? Connectivity-loss estimation under road-network disruptions

The paper investigates how graph neural networks can quickly estimate the loss of algebraic connectivity after multiple road-link disruptions, comparing learned corrections to first‑order Fiedler sensitivity with analytical baselines. Experiments on synthetic failures and real OpenStreetMap data across six countries show that residual GCN and GraphSAGE models reduce mean absolute error for spatial and targeted failures, while second‑order perturbation offers minimal improvement. The study also demonstrates that sparse scaling allows the approach to scale to 20,000 nodes and that the spectral residual acts as a domain‑sensitive inductive bias for connectivity screening.

By Van-Truong Le
arXiv Statistics ML
Sep 18

When a High Score Is an Illusion: Certifying Genuine versus Repackaged Forecasting Skill

The paper investigates how reusing observations for ranking forecasts can create artificial associations between forecast and outcome ranks. It develops theoretical conditions that preserve these associations and introduces unbiased kernel and U‑statistic estimators for interaction terms. Empirical results on a Beijing air‑quality archive show that interaction explains over 90% of shared forecast scores, and a matched null experiment demonstrates that distinct references dramatically reduce false rejections.

By Pin Ni, Francesca Medda, Ramin Okhrati