At the symposium on "Reforming learning and learning to reform" co-organized by HKU and EMB on 28 May 2005, different strategies of learning were highlighted and the knowledge building approach was one approach that attracted much interest and attention from participants. This approach can be incorporated into the school curriculum in the teaching of general studies and other subjects, including liberal studies, to foster the development of higher order thinking and lifelong learning capabilities of learners. Knowledge building is a theory of learning that incorporates a series of problem-based online discourses on a collaborative knowledge platform.