arXiv AI

When Financial Fine-tuning Fails: A Three-Level Detectability Analysis of Numerical Hallucination in Domain-Adapted Language Models

The paper investigates numerical hallucination in financial language models, comparing a base instruction-tuned model, a domain-adapted model (FT‑A), and a numeracy-enhanced domain model (FT‑A+B+C). A three-level detectability taxonomy is introduced, and the study finds that domain fine-tuning dramatically increases hallucination rates—up to 98%—and that numeracy supervision actually amplifies hallucination. Template injection is identified as a key mechanism, leading the authors to conclude that numerical hallucination stems from degraded numerical restraint rather than lack of reasoning, and they recommend comprehensive evaluation and grounding-aware deployment practices.

arXiv AI
Sep 7

Shared circuits predict whether LLMs generalize across formats in arithmetic reasoning

The study investigates whether large language models (LLMs) can generalize arithmetic reasoning across different input formats, such as numeric and verbal expressions in English, Spanish, and Italian. By using attribution patching, the researchers identified the specific internal circuits each model employs for numeric versus verbal arithmetic tasks. They found that the degree of overlap between a model’s numeric circuit and its verbal circuit predicts how well the model generalizes to verbal formats, explaining variations in performance across languages and formats without requiring labeled data.

By Andrea Gregor de Varda, Sana Pandey, Pengrui Han, Jacob Andreas, Evelina Fedorenko
Hugging Face Trending Papers
Jul 29

Diagnosing Fine-Grained Inconsistency Classification in Financial Disclosure Text

Financial disclosures contain numerical claims, temporal statements, entity references, policy commitments, and risk descriptions that may conflict in qualitatively different ways. Detecting a conflict is only the first step: review workflows may also need to determine its type, since numerical, temporal, referential, factual, and normative inconsistencies require different evidence and downstream checks.

arXiv Machine Learning
Sep 17

Attention Dispersion as a Diagnostic Signal for Hallucination in Large Language Models

The paper proposes using the temporal volatility of internal attention mechanisms—measured by an unsupervised attention dispersion metric—as a diagnostic signal for hallucinations in large language models. It demonstrates that spikes in attention entropy within intermediate layers correlate with reasoning breakdowns, and shows statistically significant AUC improvements of up to +0.076 over output-based baselines on GSM8K and MATH-500 benchmarks using the Qwen2.5 model family.

By Shardul P. More, Tanuja S. Pawar
arXiv AI
Jul 22

Prompt Design at Scale: How Format, Instruction Count, and Context Length Shape Instruction Adherence and Hallucination in Large Language Models

arXiv:2607. 19257v1 Announce Type: cross Abstract: Practitioners make three prompt-design decisions with almost no controlled evidence behind them: how to format instructions and context (markdown, plain text, prose, or tabular), how many simultaneous instructions a system prompt can carry before compliance degrades, and how much context a model can hold before recall and honesty degrade.

By Netanel Eliav
arXiv Machine Learning
Oct 8

FinVector-Market-4B: A Controlled Study of LoRA Adaptation for Structured Financial Tasks

FinVector-Market-4B adapts the Qwen/Qwen3.5-4B language model using rank‑16 LoRA on a 22,000‑example financial corpus. On a 600‑example benchmark with implicit and explicit JSON‑schema contracts, the adapted model improves JSON validity from 0% to 91.3% and boosts task‑specific metrics—FinQA exact match from 14.7% to 40.0%, calculator‑expression correctness from 48.0% to 82.7%, scenario branch‑label agreement from 20.1% to 89.5%, and implication‑direction agreement from 52.4% to 87.2%. A post‑hoc audit shows that macro‑F1 differences stem from changing label sets, and the benchmark’s generalization claims are limited by filing overlap and calculator‑target inconsistencies.

By Alina Khaybullina