As a learning theory, knowledge building is about getting learners to focus on ideas and improving ideas. On the other hand, learning activities with specific task structures form the substrate of the daily milieu for teachers and students. Would the employment of different task structures for organizing learning have an impact on the students learning outcomes in terms of knowledge building? This contribution reports on some initial findings addressing this question through a comparison of three different classroom task designs carried out under the same time frame and broad activity framework as a joint school project, Higher Order Thinking through Knowledge Building, organized and supported by CITE . Within the same broad activity framework, teachers were free to decide on the specific learning tasks they want the students to engage in as a focus for their knowledge building work in Knowledge Forum. The three task formats in the scheme are subject-based discussion, project work and artifact design.

A preliminary assessment of the students level of knowledge building was carried out on ten of the knowledge building principles delineated by Scardamalia (2002) based on an analysis scheme developed earlier by Law & Wong (2003). It was found that students involved in the artifact design task not only reached higher levels of knowledge building compared to those involved in other learning tasks in all of the knowledge building principles assessed, these students were also able to take off faster along the knowledge building developmental trajectory at a very early stage of their work. In addition, these students were able to sustain their focus on idea improvement throughout the process. This contribution will explore how and why the different task structures has contributed to different knowledge building outcomes with evidential support from the knowledge building discourse and data collected on the students learning process, including interviews.