An Independent-Constraint Framework (ICF) for empirical classification: from Solar System bodies to Cosmic evolution

The Independent-Constraint Framework (ICF) is a general-purpose, measurement-centered methodology designed to remain valid across domains where independent observables exist. Its strength lies not in predicting physical laws, but in epistemic rigor: it enforces independence, propagates uncertainties, and prevents the conflation of direct measurements with model-dependent inferences. This framework classifies physical quantities into three tiers: Tier 1 – Independent constraints: Directly measured observables with distinct physics and systematics. Tier 2 – Derived quantities: Parameters calculated from Tier 1 measurements with propagated uncertainties. Tier 3 – Model-dependent inferences: Parameters or interpretations relying on theoretical assumptions. Applied across astronomy and cosmology, ICF enables rigorous comparison of observations, identification of statistically significant gaps in parameter space, and clear separation of empirical results from inferred models. Applications for three studies: Icarus (Hierarchy / ICF concept): Established the hierarchical framework itself, providing a method to evaluate measurement independence and reliability. ApJ (Exoplanet Radius Gap): Confirms the radius gap as a robust observational feature; ICF separates directly measured radii (Tier 1) from derived densities and inferred formation/evolution models, clarifying which conclusions are robust. MNRAS (Cosmic Tensions: H₀ & S₈): Shows that H₀ and S₈ discrepancies are signals from independent measurements, not errors, guiding which future observations or models can test these tensions. ICF is transparent, reproducible, and adaptable, providing a consistent methodology for organizing, comparing, and interpreting measurements across physical scales, from planetary systems to cosmology, while maintaining methodological rigor and epistemic clarity.