Adaptive Testing for LLM Evaluation: A Psychometric Alternative to Static Benchmarks

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Li, Peiyu, Tang, Xiuxiu, Chen, Si, Cheng, Ying, Metoyer, Ronald, Hua, Ting, Chawla, Nitesh V.
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918318466662400
author Li, Peiyu
Tang, Xiuxiu
Chen, Si
Cheng, Ying
Metoyer, Ronald
Hua, Ting
Chawla, Nitesh V.
author_facet Li, Peiyu
Tang, Xiuxiu
Chen, Si
Cheng, Ying
Metoyer, Ronald
Hua, Ting
Chawla, Nitesh V.
contents Evaluating large language models (LLMs) typically requires thousands of benchmark items, making the process expensive, slow, and increasingly impractical at scale. Existing evaluation protocols rely on average accuracy over fixed item sets, treating all items as equally informative despite substantial variation in difficulty and discrimination. We introduce ATLAS, an adaptive testing framework based on Item Response Theory (IRT) that estimates model ability using Fisher information-guided item selection. ATLAS reduces the number of required items by up to 90% while maintaining measurement precision. For instance, it matches whole-bank ability estimates using only 41 items (0.157 MAE) on HellaSwag (5,600 items). We further reconstruct accuracy from ATLAS's ability estimates and find that reconstructed accuracies closely match raw accuracies across all five benchmarks, indicating that ability $θ$ preserves the global performance structure. At the same time, $θ$ provides finer discrimination within accuracy-equivalent models: among more than 3,000 evaluated models, 23-31% shift by more than 10 rank positions, and models with identical accuracies receive meaningfully different ability estimates. Code and calibrated item banks are available at https://github.com/Peiyu-Georgia-Li/ATLAS.git.
format Preprint
id arxiv_https___arxiv_org_abs_2511_04689
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Adaptive Testing for LLM Evaluation: A Psychometric Alternative to Static Benchmarks
Li, Peiyu
Tang, Xiuxiu
Chen, Si
Cheng, Ying
Metoyer, Ronald
Hua, Ting
Chawla, Nitesh V.
Computation and Language
Artificial Intelligence
Evaluating large language models (LLMs) typically requires thousands of benchmark items, making the process expensive, slow, and increasingly impractical at scale. Existing evaluation protocols rely on average accuracy over fixed item sets, treating all items as equally informative despite substantial variation in difficulty and discrimination. We introduce ATLAS, an adaptive testing framework based on Item Response Theory (IRT) that estimates model ability using Fisher information-guided item selection. ATLAS reduces the number of required items by up to 90% while maintaining measurement precision. For instance, it matches whole-bank ability estimates using only 41 items (0.157 MAE) on HellaSwag (5,600 items). We further reconstruct accuracy from ATLAS's ability estimates and find that reconstructed accuracies closely match raw accuracies across all five benchmarks, indicating that ability $θ$ preserves the global performance structure. At the same time, $θ$ provides finer discrimination within accuracy-equivalent models: among more than 3,000 evaluated models, 23-31% shift by more than 10 rank positions, and models with identical accuracies receive meaningfully different ability estimates. Code and calibrated item banks are available at https://github.com/Peiyu-Georgia-Li/ATLAS.git.
title Adaptive Testing for LLM Evaluation: A Psychometric Alternative to Static Benchmarks
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2511.04689