Consumer appraisal of drinking water: multidimensional scaling analysis

Two non-quantitative, non-descriptive procedures, similarity sorting and preference ranking, were used to compare the tastes of 13 different water types. Each procedure was conducted with a different set of completely untrained assessors. A total of 25 assessors took part in the sorting procedure and 87 in the ranking procedure. After multidimensional scaling there was good agreement between the spatial configurations of sample types given by the two procedures. In both configurations there was distinct clustering of the different water types. Bottled and untreated waters were preferred to distilled and tap waters by the majority of the assessors. Carbon filtration did not appear to make a large improvement to the acceptability of tap and distilled waters, but did alter the character of tap water as perceived by the assessors. It is concluded that the procedures and analyses are efficient and economical methods of obtaining detailed information about sensory differences among water types and the perception of water quality and are suitable for use with untrained assessors and large numbers of sample types.