Establishing traceability of self-reported dependence measurement through the use of crosswalks
Measurement in the social sciences has been characterized by deficient justification and underdeveloped conceptual theories. Instruments supposed to measure the same measurand typically do not provide comparable measurements. From the perspective of metrological traceability, the state of affairs has thus been unsatisfactory. Today, better instruments can be developed as psychometrics provides tools for invariant measurement (Rasch measurement theory), where measurements are justifiable, linear, and sample-independent. Different instruments can be linked to a common metric of the measurand by means of co-calibration of item parameters. Such linkages, referred to as crosswalks, are an important and practically useful contribution to traceability, when common references have not been developed, yet. The measurement of dependence on tobacco and/or nicotine-containing products through self-report instruments illustrates the limitations of traditional measurement, how they can be overcome by new instrument development, and how a network of crosswalks with existing legacy instruments can be established.