This research focuses on a Knowledge Building pedagogical approach and investigates ways to boost students’ competencies in knowledge creation processes, specifically their ability to contribute productively to high-level explanation-seeking discourse. This study uses a design-based methodology to explore how pedagogical and technological innovations can enhance students’ ways of contributing to knowledge building discourse, and examines whether expanding students’ contribution repertoire helps them to advance community knowledge in general. Gains associated with a Knowledge Building approach for secondary and post-secondary students are widely documented. This research adds to this body of literature by showing how a Knowledge Building approach can be productively engaged at the early primary level. This work also contributes to studies exploring automated feedback and assessment tools that can help boost student capacities for building new knowledge. The research was conducted in three main phases. The first phase mapped the ways that students from Grades 1-6 (n = 102) contribute to their naturally occurring Knowledge Building discourse in order to provide baseline data for subsequent design experiments. The following two phases corresponded to two design iterations that involved work in Grade 2 science and that tested different types of formative feedback. Design Cycle 1 (n = 42) focused on testing supports to boost low-frequency contribution types. Design Cycle II (n = 43) aimed to reproduce and improve results from the first iteration. In both design cycles, pedagogical supports included whole-class metadiscourse sessions, while technological supports consisted of contribution and content-oriented feedback tools that offered students a meta-perspective on their own discourse, including Word Clouds (Cycle 1), Concept Clouds (Cycle 1-2), visualizations produced by the Metadiscourse Tool (Cycle 1-2), and verbal scaffolds (Cycle 1-2). Analyses of data revealed that these supports helped students to significantly increase their engagement with targeted contribution types, diversify their general contribution repertoire, and advance collective knowledge beyond that attained by their peers in prior years. This research provides empirical evidence that Knowledge Building inquiry can be effectively engaged at the primary level, and offers usable artifacts tested and shown to be conducive for helping young students raise the level of their Knowledge Building discourse.