This chapter discusses one of the key research foci of the Learning Sciences and Technologies academic group at the National Institute of Education, Nanyang Technological University in Singapore. Based on our empirical research, we describe two vignettes that examined student cognition in computer-supported collaborative learning environment. We define student cognition as students exhibited critical thinking level and knowledge building in online discussions. In the first vignette, we describe certain discussion guidelines, as well as student facilitation techniques that could help foster in-depth levels of critical thinking in online discussion forums. In the second vignette, we examine the levels of knowledge building demonstrated by students and how these levels might be influenced by the nature of the task or activity undertaken by the students. [For the complete volume, "Educational Media and Technology Yearbook, Volume 36, 2011," see ED597737.]