arXiv Computation and Language

MetroLLM-Bench: Evaluating Language Models as Transit Kiosk Runtimes

MetroLLM-Bench is a 955‑case benchmark designed to evaluate language models as the policy layer of transit kiosks across six real metro systems, covering routing, fare calculation, disruptions, accessibility, and adversarial input. The benchmark includes 14 deterministic scoring components (Tier 1) and 8 semantic‑quality components (Tier 2), with a 75/25 split for training‑data generation and held‑out evaluation. Twenty‑six models from six vendors were tested, and a 4B Qwen 3.5 student fine‑tuned via PEFT outperformed GPT‑5.6 on Tier 1 and matched GPT‑5.4 on the combined score, while larger models offered no further improvement.

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
arXiv AI
Jun 26

NebulaExp-8B: An Empirical Post-Training Pipeline via Full-Scale Ablation Research

arXiv:2606. 26671v1 Announce Type: new Abstract: Post-training alignment determines the reasoning and human preference following capabilities of large language models, yet most existing works withhold detailed data construction, filtering rules and training recipes, which hinders community reproducibility and lightweight model optimization.

By Qiaobo Hao, Yangqian Wu, Shunyi Wang, Zhongjian Zhang, Ziqun Li, Yayin He, Muqing Li, Chen Zhong
arXiv Computation and Language
Sep 7

Unified Deployment-Aware Evaluation of Open Reasoning Language Models

The paper presents a unified evaluation of seven open reasoning language models across four benchmarks (ARC-Challenge, GSM8K, MATH levels 1–3, and TruthfulQA MC1) using a consistent 238-example subset and three prompting strategies (zero-shot, chain-of-thought, few-shot CoT). It reports not only accuracy but also Wilson confidence intervals, latency, VRAM usage, weighted aggregate performance, Pareto-efficient points, prompt-sensitivity, and compatibility diagnostics, revealing that Gemma-4-26B-A4B tops the weighted score while Gemma-4-E4B offers a strong practical trade-off. The study emphasizes that model rankings shift with prompting strategy and that deployment trade-offs remain crucial, advocating for a deployment-aware, multi-objective evaluation framework rather than a single-score leaderboard.

By Md Motaleb Hossen Manik, Ge Wang
arXiv AI
Aug 28

Zero-Shot Self-Orchestration with Ledger-Based Control for Improved LLM Coding Performance

The paper evaluates a manager‑worker scaffold that uses a shared filesystem workspace to orchestrate multi‑agent large language model (LLM) coding tasks without training or tuning. Across nine models—including five open‑weight and four closed‑weight systems—the scaffold yields statistically significant accuracy gains for some models (e.g., Qwen3.8‑27B, GPT‑5.6‑Luna, GPT‑5.6‑Terra, Kimi‑K3, Minimax‑M3) while producing null or negative effects for others (e.g., Qwen3.6‑35B). The study shows that the manager can triple token usage but still achieves higher accuracy at a fraction of the cost compared to larger single‑pass models, with key mechanisms identified as context management and problem decomposition.

By Victor Gao (Sang Won), Vida Khosrowshahi (Sang Won), Ali Khosrowshahi (Sang Won), Xihao Sun (Sang Won), Juhyun Lee (Sang Won), Simon (Sang Won), Lee
arXiv AI
Jun 3

CoEval: Ranking Language Models for Custom Tasks Without Labeled Data or Trustworthy Benchmarks

arXiv:2606. 03650v1 Announce Type: cross Abstract: Choosing or ranking language models for a specific application is hardest when no task-specific labeled data exists, and standard public benchmarks cannot be trusted, their items having likely leaked into pretraining, so scores reflect memorization rather than fitness.

By Alexander Apartsin, Yehudit Aperstein
arXiv Machine Learning
Aug 19

OraclePhys: A Systematic Framework for LLM Fine-Tuning on Structural Mechanics

OraclePhys is a fine‑tuning framework for large language models on structural mechanics, comprising a graded benchmark (OraclePhys‑Bench), a 30K supervision dataset (OraclePhys‑30K), and a controlled training study. The study shows that the form of the label’s answer, rather than its length, determines what the model learns, and that certain training objectives can produce models that match or exceed existing LLMs on spatial structural response tasks. The trained 8B model reaches the data‑precision frontier, outperforming zero‑shot and 32‑shot baselines at a specialist level.

By Mingyu Li, Guorui Song, Jing Lin, Haoqian Wang
arXiv AI
Jun 3

Synthesize and Reward -- Reinforcement Learning for Multi-Step Tool Use in Live Environments

arXiv:2606. 03892v1 Announce Type: cross Abstract: Training LLMs to orchestrate multi-step tool calls is held back by three coupled obstacles: realistic stateful execution environments are costly to build, synthetic training queries are often detached from the server's actual state (so the generated tool calls fail to execute), and recall-based RL rewards incentivize verbose tool-calling patterns.

By Ibrahim Abdelaziz, Asim Munawar, Kinjal Basu, Maxwell Crouse, Chulaka Gunasekara, Suneet Katrekar, Pavan Kapanipathi