CATALYST brings together deeply experienced community-partners engaged daily in curating very large online communities on social innovation and citizen engagement platforms, and leading academic research partners specialized in Collective Intelligence (CI).The project will undertake technological developments aimed at radically improving collaborative knowledge creation through ground-breaking functionalities intended to mobilize CI for the public good, and will test these next generation solutions in authentic, real world settings.Within a CI Spectrum ranging from Sensing to Collective Action, CATALYST focuses on Contested CI (Sensemaking and Ideation), which recognises the centrality of deliberation, argumentation and public debate. In order to understand and support the dynamics of multilingual social and deliberation networks, the project will look at:• Human-assisted online tools to inexpensively harvest the vast amount of data and knowledge that develop in social media, and facilitate collective ideation, creativity and citizen engagement;• Analytics to measure the quality of the collective intelligence dynamics back to the community to make the collaborative process significantly more effective.Academics and community-partners will be in close dialogue with software developers. Community-partners' "pain points" have already been identified. A mapping between pain points and research concepts will be established, moving to use cases, which will drive rapid prototyping and testing via an Agile methodology.CATALYST will deliver an ecosystem of CI services that will augment partners' platforms with Web-based Annotation tools; Recommenders to help users prioritise attention; Online creativity triggers; Interactive Visualizations, and Social Network and Deliberation Analytics. A coherent user experience will be delivered through a CI Analytics Dashboard.All project developments will be carried out under an open source / free software license.