Building on Common Ground for Collective Impact - Action Research Common ground In late 2015 members of the South Island (New Zealand) Public Health Partnership (established in 2010 by the 3 Public Health Units , in conjunction with their funder, the Ministry of Health, and their 'backbone' organization, the South Island Alliance of 5 District Health Boards) agreed to consider how the Partnership could develop to achieve stronger collective impact. Building- tools and techniques A workshop was held in February 2016 during which the shared vision of an alliance was identified. Once fully discussed, members welcomed the opportunity that alliancing provides to create decision making machinery without formal merger. Evidence-based research papers were referenced and stimulated shared thinking and dialogue about collective impact and influence in health. A workshop, led by an alliancing technical expert was held in April 2016. Following this, members agreed to revise the Terms of Reference, thus significantly widening the group membership and scope. This mapped out the steps to develop a formal alliance. Members were positive and optimistic about the future. The need for detailed planning was met by active participation in frequent 'in person' meetings called at short notice involving travel. The Group's discourse culminated in a proposal to the governance group to expand the scope and membership, which was approved in August 2016. Key messages 1. Evidence-based research can accelerate shared thinking, discussion and dialogue 2. Getting the 'soft stuff' right (frequent, 'in person' meetings, with opportunity for informal discussion) can positively impact on progress. 3. Working on collective impact encourages engagement, energy and optimism.