Abstract
Things (objects, phenomena, events, processes, ...) are described by values of characteristics; when the evaluation is realized by a measurement, the description assumes a degree of objectivity making it a good tool of intersubjective communication. "Qual ity" is a characteristic typically adopted to express the degree of compliance of the considered thing with the requirements arising from its design. But usually the quality is evaluated without a well defined method, possibly recurring to the expert's ex perience: in such cases, the meaning of the quality values is inherenty subjective. In this work the problem of measurability of quality is discussed: the problem is introduced in metrological terms; then a model is proposed to interpret the quality as a characteristic that can be evaluated by derived measurements. Finally, some topics for further analyses on such a model are pointed out.