New Performance Index "Attractiveness Factor" for Evaluating Websites via Obtaining Transition of Users' Interests. - Akihiro Yoshida; Tatsuru Higurashi; Masaki Maruishi; Nariaki Tateiwa; Nozomi Hata; Akira Tanaka; Takashi Wakamatsu; Kenichi Nagamatsu; Akira Tajima; Katsuki Fujisawa (Data Sci. Eng., 2020)