Temporal Coverage and Forcing Completeness Govern Inference From Dynamic Surface‐Tension Curves

ABSTRACT Dynamic surface‐tension and interfacial‐tension curves are commonly interpreted as adsorption, transport, or interfacial‐restructuring kinetics, but the claim supported by a curve depends on temporal coverage and the forcing history. We formalized this requirement as claim‐relative information sufficiency and tested it on 979 curated literature series representing 233 distinct surfactants. Predeclared screening retained 684 curves; 464 curves from 78 publications formed the development set and 220 curves from 43 nonoverlapping publications formed locked validation. Among development curves, 57.3% of model‐family decisions were ambiguous, and only 22 of 123 bi‐exponential winners under the small‐sample corrected Akaike information criterion (AICc) satisfied all requirements for two resolved modes. With eight observations, median held‐out normalized root‐mean‐square error (NRMSE) in locked validation was 0.327 for early‐only, 0.311 for late‐only, 0.0177 for broadband, and 0.0189 for adaptive matched‐scale sampling. This ordering persisted within nonionic, cationic, and anionic strata and after structural sensitivity analyses excluding EO‐rich nonionic and alkyl‐sulfate records. A frozen transfer analysis retained six curves from four independent publications spanning polymer‐surfactant coassembly, redox‐controlled host‐guest reassembly, biological‐detergent adsorption, and nonequilibrium surfactant partitioning. Broadband and adaptive NRMSE remained low (0.0249 and 0.0216), while AICc and blocked cross‐validation disagreed on the response family for all six curves. Paired n ‐hexane experiments showed that evolving boundary conditions can be absorbed into apparent kinetics. Broad temporal coverage protects finite‐window prediction, but stable kinetic and mechanistic claims additionally require measured or stationary forcing and orthogonal observables.