SOURCE-LINKED INTELLIGENCE

Exact Risk Ratios for Weighted Data Selection in Linear Regression

arXiv · AI, language, vision and robotics · article · Aug 28, 2026 · UTC

Hanneke, Moran, Shlimovich and Yehudayoff (COLT 2025) posed the following open problem. A selector sees a finite dataset $D \subseteq \mathbb{R}^d \times \mathbb{R}$, picks at most $n$ examples together with nonnegative weights, and hands the weighted least squares objective to the minimum-norm ERM. Writing $F_w(d,n)$ for the worst-case ratio between the loss of the returned predictor on all of $D$ and the optimal loss, they proved $F_w(d,n)=\infty$ for $n<d$, $F_w(d,d)=d+1$ and $F_w(d,n)=1$ for $n \ge 2d$, and asked for the value in the open regime $d<n<2d$. We determine this value in several

Read original source ↗ Open in workspace

recordType

paper

region

Global