COSMosFL demonstrates how ensembles of smaller, open-source language models can effectively compete with large closed-source models for software fault localization.

• Combines multiple small language models to achieve performance comparable to larger models
• Reduces deployment costs, energy consumption, and security concerns
• Enables local deployment without compromising effectiveness
• Demonstrates practical viability for software engineering tools without reliance on massive language models

This research matters because it provides an accessible, cost-effective approach for building AI-powered debugging tools that respects privacy concerns while maintaining high performance standards.

COSMosFL: Ensemble of Small Language Models for Fault Localisation