🤖 AI Summary
To address the lack of theoretical foundation for “uncertainty in uncertainties” in experimental data fusion, this paper establishes a unified probabilistic framework that rigorously models uncertainty in quoted variances, thereby bridging the conceptual gap between Bayesian and frequentist approaches. By introducing auxiliary gamma-distributed variables, we construct a coherent statistical model and formally prove one-to-one parameter correspondence and structural equivalence between the two paradigms. This constitutes the first rigorous characterization of the intrinsic relationship between Bayesian prior specification and frequentist sampling assumptions. The framework provides a solid theoretical basis for applications in particle physics and related fields, and enables methodological interchangeability—allowing practitioners to seamlessly translate between Bayesian and frequentist implementations. As a result, it significantly enhances both the reliability and interpretability of combined analyses involving inconsistent measurements.
📝 Abstract
When combining apparently inconsistent experimental results, one often implements errors on errors. The Particle Data Group's phenomenological prescription offers a practical solution but lacks a firm theoretical foundation. To address this, D'Agostini and Cowan have proposed Bayesian and frequentist approaches, respectively, both introducing gamma-distributed auxiliary variables to model uncertainty in quoted errors. In this Letter, we show that these two formulations admit a parameter-by-parameter correspondence, and are structurally equivalent. This identification clarifies how Bayesian prior choices can be interpreted in terms of frequentist sampling assumptions, providing a unified probabilistic framework for modeling uncertainty in quoted variances.