Schoenberg names 'accepted actuarial practice' as the direct source of his own 'ordinary' vs. 'smoothing' interpolation-formula distinction

schoenbergb-splinesplinesgraduationactuarial-scienceosculatory-interpolationhistory-of-mathematics

Defining the split between formulas that reproduce given data points exactly and formulas that smooth them, Schoenberg writes in Part A: "We shall follow the accepted actuarial practice of referring to (3) as an ordinary interpolation formula if (3) reproduces exactly the given ordinates {y,, ]. Otherwise we call (3) a smoothing interpolation formula." (The bracket is an OCR artifact of the scanned journal PDF; the sentence is otherwise intact.)

This goes beyond borrowing a single word — Schoenberg states outright that he is following existing actuarial convention for a core piece of his own formal apparatus, the ordinary/smoothing split that structures the rest of the paper's formula classification. Part B's footnote mapping his terms onto Greville's ("ordinary"/"modified" ↔ "ordinary"/"smoothing") shows the mapping held across both papers, not just as a one-off acknowledgment in Part A. Compare claim-schoenberg-1946-credits-jenkins-1926-greville-1944-as-osculatory-interpolation-predecessors, which documents the same debt at the level of citation rather than terminology.