This study integrates the purposes of communication, i.e. in-class and on-line discussions, with problem solving skills in the process of learning professional knowledge of pre-service teachers. It attempts to foster both comprehension of professional knowledge and the attitude of contextualizing knowledge with situational factors. More importantly, this study hopes to help pre-service teachers with the development of critical reflection skills through cooperation with others in inquiry-based tasks. The results from posted messages on the on-line forum indicate the growth of knowledge during the period of the study. In the messages shared in the post-session forum, pre-service teachers provide more in-depth viewpoints and support their arguments with examples. Also, they were able to contextualize professional knowledge by relating it to their own context. The results of this study highlight the importance of having problem-solving skills and using cooperative learning in learning professional knowledge for pre-service teachers. It also fosters the spirit and skills for life-long learning.