Measurement of Naturalness: Physics and Perception

This paper presents the outcomes of an EU project (‘Measurement of Naturalness’, or MONAT), which aimed to develop a measurement system to predict the perception of naturalness for a range of materials, based on an understanding of the relationship between the physical attributes of the material and the human perceptual responses. The project included the establishment of novel measurement instrumentation to characterise the perceptually-relevant properties of the materials. New data analysis and modelling techniques were also developed to isolate the key physical properties of a material that influence the perception of naturalness, and to build mathematical models to describe the perceived naturalness in terms of these properties. The predictive power of the models proved to be extremely good, with correlation values in excess of 0.8 for new samples with properties similar to those used to develop the models, and reduction of error values above 70% for samples with properties falling outside this gamut.