Success of learning activities depends on whether "emergent division of labor" is smooth or not, in discovery learning in which learners construct collaboratively their knowledge synchronously. Emergent division of labor is activated by mutual "awareness" of other groups' activities. Not all learners are good at being aware of others' activities. Then not a few learners need some supports by providing awareness information so that they can improve the degree of successes of their learning activities with emergent division of labor. This paper reports 1) the result of a consideration to discovery learning activities in CSCL from the framework of emergent division of labor, 2) a model of emergent division of labor in discovery learning activities, 3) functions for the synchronous CSCL system "Kneading Board" which activates emergent division of labor, and 4) practice cases of the system.