Psychological bias caused by notification of odor name in sensory evaluation test of odor

Abstract

“Tatami” is a traditional Japanese building material used as a floor mat made with rush. It used to be said that the smell of tatami is preferred by many Japanese, because almost all Japanese houses have had tatami rooms since early times. In this paper, the psychological bias of notification of material name was investigated. This kind of psychological bias seems to be a very important factor that affects the result of sensory test. In the sensory evaluation of odor, the name of the source material is usually concealed, but in this paper, odor evaluation tests were conducted where the source material name is given to the subjects before its evaluation. The usual test that the source material name is not given was also conducted using the same panels. The odors emitted from three building materials that included white cedar, tatami and concrete were selected. Odor intensity, impressions, hedonics and acceptability were voted by eight young subjects. As expected, the tatami odor evaluation results indicated that the odor acceptability rose when the subjects were notified of the material name before evaluation. The acceptability of the concrete odor tended to drop conversely when the material name was given beforehand. In addition to above investigations, another series of tests were conducted where the fake name was told to the panels before testing using odor from tatami and concrete. The fake names were garbage instead of tatami and cypress instead of concrete. It was turned out that the preference of the material has quite a large effect on the odor evaluation results.