arXiv Computation and Language

Wrong Together: Shared Bias in User Simulation

The paper investigates whether disagreement among user simulators can flag unreliable estimates of group response proportions and group differences. Using six language‑model simulators on 60 questions across 12 countries, disagreement more accurately predicts invalidity for group differences (AUC 0.87) than for single group proportions (AUC 0.71). The authors find that shared bias among simulators can obscure errors, but correcting for this bias reduces prediction error without altering disagreement signals.

arXiv AI
Sep 18

Language-model groups overstate consensus when replaying human deliberation on a reasoning task

The study compares human deliberation in Wason selection tasks with large language model (LLM) agent groups that are seeded with participants’ pre-discussion beliefs. Across various scoring definitions, human consensus rates ranged from 24.0% to 57.0%, whereas LLM agents consistently achieved higher consensus, with gaps of 34–44 percentage points in two sensitivity analyses. Even when early stopping was removed or memorizable answers were eliminated, LLM groups still reached near-unanimous agreement, often on incorrect answers, indicating that simulated consensus does not reflect collective accuracy.

By Tengfei Shao
arXiv Machine Learning
Jun 30

Beyond the Mean: Three-Axis Fidelity for Aligning LLM-Based Survey Simulators from Small Pilot Data

arXiv:2606. 28963v1 Announce Type: cross Abstract: Large language models (LLMs) are increasingly used to simulate social survey responses, yet their outputs exhibit systematic biases: marginal distributions are skewed, response variance is poorly calibrated, and predictor-outcome relationships are attenuated.

By Eun Cheol Choi, Youngrae Kim, Prabhu Pugalenthi, Hong-En Chen, Bo-Ruei Huang
arXiv AI
Sep 30

Population Fidelity: Evaluating Population Representativeness in LLMs

The paper introduces Population Fidelity, an evaluation framework for assessing how well large language models (LLMs) represent human population attitudes. It focuses on three dimensions: group-level accuracy, between-group variation, and the structure of that variation. Using the framework, the authors replicate a prior study on machine bias and test cultural fine-tuning, finding that while fine-tuning improves overall alignment, it does not enhance representation of within-population differences.

By Neemias B. da Silva, Martin Lukk, Ali Sutani, Abhishek Moturu, Harris Yang, Daniel Silver, Matt Ratto, Thiago H. Silva
arXiv AI
Oct 2

What Does a Sharing Question Add? Auditing LLM Survey Scores for Misinformation

The study examines whether asking large language models (LLMs) to predict whether readers would share misinformation adds useful information beyond predicting credibility. Eight LLM versions were audited on 290 synthetic misinformation articles, yielding 1,256 paired survey responses. While credibility scores explained a substantial portion of sharing variation, adding sharing predictions to credibility did not meaningfully reduce error, indicating that sharing answers contain structured variation but lack established incremental validity for human sharing.

By Zonghuan Xu, Xiang Zheng, Yutao Wu, Xingjun Ma
arXiv AI
Jul 24

Response drift across frontier large language models

arXiv:2607. 20454v1 Announce Type: cross Abstract: All frontier large language models (LLMs) exhibit response drift -- producing outputs that deviate from expert-validated references -- yet the magnitude and structure of this drift remain uncharacterised by systematic human evaluation.

By Mohammed Aledhari, Ali Aledhari, Fatimah Aledhari, Gowtham Venkat Eathamokkala, Mohamed Rahouti
arXiv Computation and Language
Sep 18

An Analysis of Training-Free Self-Reported Confidence in Language Models

The paper investigates whether language models’ self-reported confidence is meaningful without additional training. By evaluating three training‑free signals—direct verbalization, post‑hoc probability estimates, and agreement across multiple generations—on 100 TriviaQA questions, the authors find that direct verbalization alone achieves high AUROC scores (0.956 and 0.937) for correctness prediction, while agreement-based methods perform noticeably worse. Re‑eliciting confidence for the same answers shows modest score shifts and occasional decision flips, and an audit of biography claims reveals only a small confidence gap between supported and contradicted statements.

By Lukas Meyer, Sofia Rossi, Wei Chen, Thomas Laurent, Yiming Li