1. Department of Economics, Aoyama Gakuin University, Tokyo, Japan.
2. Graduate School of Applied Informatics, University of Hyogo, Kobe, Japan.
3. Osaka School of International Public Policy, Osaka University, Osaka, Japan.
4. Center for Education of Information Literacy, International University of Health and Welfare, Tokyo, Japan.
5. Kyoto University of Education, Kyoto, Japan.