coverage

This paper identifies the 'modal ceiling' and 'correlation ceiling' in test-time scaling for reasoning models, showing that beyond a few dozen samples, additional sampling does not improve selection accuracy and can even harm it, highlighting the identifiability gap between generating and recognizing correct answers.

This paper identifies a blind spot in reference-free faithfulness metrics: they only measure precision (whether claims are supported) but not recall (coverage of relevant facts). The authors introduce a complete-oracle evaluation using Formula 1 telemetry and weather data, showing that high-precision models often have poor coverage, and propose a combined metric.