Man as a Measurement Instrument

Demands for quality assured measurement are increasing, not only from sectors such as health care, services and safety, where the human factor is obvious, but also from manufacturers of traditional technical products of all kinds who realize the need to assure the quality of their products as perceived by the customer. The metrology of human-based observations is however in its infancy. This article reviews how this can be tackled with a measurement system analysis approach, particularly where Man acts as a measurement instrument. Connecting decision risks when handling qualitative observations with information theory, perceptive choice and generalized linear modelling – through the Rasch invariant measure approach – enables a proper treatment of ordinal data and a clear separation of person and item attribute estimates. This leads in turn to opportunities of establishing measurement references, and the metrological quality assurance that is urgently needed in many contemporary applications