Abstract
Residents in Tokyo and Saitama Pref. were segmented by the patterns of tap water drinking and the factors that affect to the varieties of the patterns were explored with the object of users' general/regional environmental consciousness or health consciousness. A model obtained by Bayesian network analyzed the effect to the choice probability for each segment. Unease of qualities of tap water mainly affects on the behaviors, and reduction of the unease enables to arise the ratio of direct tap water drinking from 40% up to 55%. While, environmental consciousness is most affective factor to grow the unease for quality of tap water. Measures to promote rigid understandings and calm judgment to environmental issues would be required for eliminating the unease.
