Stop Guessing When to Stop Testing: Efficient Model Evaluation with Just Enough Data

2026-07-09

AI Summary

Fixed-size benchmarking in model evaluation often fails to balance efficiency, statistical reliability, and diverse objectives, leading to either excessive resource consumption or unreliable results. This work proposes the first adaptive framework that integrates sequential testing into AI model evaluation, dynamically allocating evaluation data based on stopping criteria tailored for model ranking and selection tasks. By combining sequential hypothesis testing, minimum detectable effect analysis, and diminishing returns detection, the method achieves substantial gains in efficiency without compromising rigor. Empirical validation on the Open VLM Leaderboard demonstrates an 80% reduction in computational cost while maintaining a confidence interval width of 2.5 points, significantly enhancing both the practicality and scalability of model evaluation.

Abstract

The inherent rigidity of fixed-size benchmarks makes them an inefficient tool for model evaluation. Diverse evaluation objectives, including model ranking, model selection and testing throughout development, demand varying levels of statistical power. The mismatch between fixed sample sizes and these diverse needs results in either excessive computational cost or compromised reliability - a critical concern for model evaluation. To overcome these limitations, we call for adoption of sequential testing in our field. We provide an adaptive evaluation framework, that provides a principled way to navigate the trade-off between efficiency and reliability in model evaluation. Our framework combines the established statistical paradigm of sequential testing with stopping criteria tailored to common evaluation needs such as diminishing returns detection, and minimum detectable effect size. We demonstrate its ability to adaptively manage the efficiency-reliability trade-off on the Open VLM Leaderboard, including, for example, a 80% reduction in computational cost compared to fixed-size evaluation (with a 2.5-point CI width allowance) while maintaining statistical significance.

Problem

• model evaluation
• fixed-size benchmarks
• statistical power
• computational cost
• reliability

Innovation

• sequential testing
• adaptive evaluation
• model evaluation
• stopping criteria
• statistical efficiency