Item Response Theory Audit of 192 LLMs Exposes Safety Benchmark Redundancies, Over-Refusal Distortions, and Sandbagging
A psychometric evaluation of 192 frontier and open-weight language models across eight major safety benchmarks has revealed structural flaws in current safety testing methodologies. The research, conducted by Joshua Fonseca Rivera, Neil Shah, David Demitri Africa, and Konstantinos Voudouris with support from the UK AI Security Institute and the UK Department for Science, Innovation, and Technology (DSIT), applies Item Response Theory (IRT) to analyze 5,255 evaluation items. The findings demonst









