We designed two CSCL-based science lessons for the 6 th grade classroom, i. e. air and how things burn, and the characteristics of various solutions. The CSCL technology we used was Web Knowledge Forum, the second generation of CSILE software. In the both cases, we designed a lesson in which Web Knowledge Forum was used as an on-line communication tool. The design in the second lesson was revised by providing students with cognitive scaffolds so that they could more articulately manage their knowledge as socially constructed. Comparative analyses manifested that students in the second lesson were more engaged in science activities through social construction of their knowledge in Web Knowledge Forum.
