Functions of units, scales and quantitative data: Fundamental differences in numerical traceability between sciences

Abstract Quantitative data are generated differently. To justify inferences about real-world phenomena and establish secured knowledge bases, however, quantitative generation must follow transparent principles applied consistently across sciences. Metrological frameworks of physical measurement build on two methodological that transparent, traceable—thus reproducible processes for assigning numerical values to measurands. Data traceability requires implementation unbroken, documented measurand-result connections attributing results research objects. Numerical the assigned known standards results' public interpretability. This article focuses traceability. It explores how units scales defined an internationally shared understanding quantities. The underlying scrutinise psychological social-science practices quantification. Analyses highlight heterogeneous notions ‘units’ ‘scales’ identify four functions; they serve as (1) ‘instruments’ enabling empirical interactions with study properties; (2) structural format; (3) conceptual (4) conventionally agreed reference These distinct functions, employed in different stages, entail (if any) rationales establishing their meaning. common recoding scale categories tests questionnaires creates scores devoid information. meaning is created through numeral-number conflation differential analyses, producing lack systematic relations quantity regarding properties. findings new directions conceptualisation psychology social