ABSTRACT
This chapter illustrates how psychophysicists use magnitude estimation to assess the relation between apparent physical viscosity and perceived sensory viscosity. It deals with one sensory continuum; the odor strength of n-propyl alcohol is similar to the many hundreds of studies published in the scientific literature. The quality control engineer, wanting to ensure that each production batch of products retains its sensory integrity, has to know whether deviations of physical magnitudes correspond to small, moderate, or large deviations in sensory intensity. The quality control engineer would like to develop ratio scales of perception in order to learn which physical changes are most able to provoke large sensory responses. Exponents for power functions are assumed to be reliable from study to study and thus provide insight into how we transform physical stimuli into sense magnitude. Magnitude estimation allows the panelist to rate the profile of the "ideal product", using the same scales that the panelist used to rate actual products.
