  Although Large Language Models (LLMs) are becoming increasingly powerful,
they still exhibit significant but subtle weaknesses, such as mistakes in
instruction-following or coding tasks. As these unexpected errors could lead to
severe consequences in practical deployments, it is crucial to investigate the
limitations within LLMs systematically. Traditional benchmarking approaches
cannot thoroughly pinpoint specific model deficiencies, while manual
inspections are costly and not scalable. In this paper, we introduce a unified
framework, AutoDetect, to automatically expose weaknesses in LLMs across
various tasks. Inspired by the educational assessment process that measures
students' learning outcomes, AutoDetect consists of three LLM-powered agents:
Examiner, Questioner, and Assessor. The collaboration among these three agents
is designed to realize comprehensive and in-depth weakness identification. Our
framework demonstrates significant success in uncovering flaws, with an
identification success rate exceeding 30% in prominent models such as ChatGPT
and Claude. More importantly, these identified weaknesses can guide specific
model improvements, proving more effective than untargeted data augmentation
methods like Self-Instruct. Our approach has led to substantial enhancements in
popular LLMs, including the Llama series and Mistral-7b, boosting their
performance by over 10% across several benchmarks. Code and data are publicly
available at https://github.com/thu-coai/AutoDetect.
