arXiv Computation and Language
Sep 25

StepCOPS: Closed-Testing Lower-Tail Certificates for Language-Model Policy Selection

StepCOPS is a new method for selecting a language‑model policy from many checkpoints, prompts, and decoding rules by providing closed‑testing lower‑tail certificates. It uses an independent proposal split to nominate a lower‑tail floor for each candidate, applies exact binomial tests on a fresh certification split, and employs Holm’s step‑down procedure to certify a set of floors. In experiments across 24 configurations and 11 benchmarks, StepCOPS achieves 96.4% selected‑policy coverage, raises the certified floor by 1.5 points over prior methods, stays 0.6 points below a large‑reference jury oracle, and abstains in 2.4% of trials.

By Ibne Farabi Shihab, Sanjeda Akter, Anuj Sharma
arXiv AI
Aug 24

UpgradeBench: A Decision-Centric Benchmark for Upgrading Fine-Tuned LLM Specialists

UpgradeBench is a decision‑centric longitudinal benchmark that evaluates how fine‑tuned language‑model specialists should be handled when new base‑model releases occur. It covers four consecutive Qwen releases, a continuation checkpoint, six tasks, two model sizes, and OLMo checkpoints with known training lineage, and examines whether retraining, adapter transfer, or other recovery strategies improve specialist performance. The benchmark reveals that upgrade gains vary by task and release interval, that direct adapter copying is sensitive to pretraining distance, and that teacher relabeling can recover specialists without new annotations. "whyItMatters":"The study provides actionable insights into the cost‑effective management of specialist models across model releases, showing how to balance retraining effort with performance gains."

By Ye Chen, Weining Zhang
Hugging Face Trending Papers
Jun 10

Layer-Isolated Evaluation: Gating the Deterministic Scaffold of a Production LLM Agent with a No-LLM, Regression-Locked Test Harness

End-to-end task-success is the dominant way to evaluate LLM agents, but one aggregate number tells you that an agent regressed, not where. We present layer-isolated evaluation: a deployed ordering agent is decomposed into a fixed taxonomy of layers (ontology, intent, routing, decomposition, escalation, safety, memory, and cross-cutting envelope/defense), each exercised by its own assertion slice in a deterministic, no-LLM "pure" mode.