Mikihiko Mori Kokolo Ikeda Gaku Hagiwara Masaki Saga Tetsutaro Uehara Hajime Kita Socialized Computers and Collaborative Learning. 48-61 2008 JSAI http://dx.doi.org/10.1007/978-3-642-00609-8_6 conf/jsai/2008 db/conf/jsai/jsai2008.html#MoriIHSUK08