Learning outcomes at school are the result of what happens in classrooms, thus only reforms that are successfully implemented in classrooms can be expected to be effective. One of the key conclusions of the Summit was that teacher engagement in the development and implementation of educational reform is crucial and school reform will not work unless it is supported from the bottom up. This requires those responsible for change to both communicate their aims well and involve the stakeholders who are affected. But it also requires teachers to contribute as the architects of change, not just its implementers. Some of the most successful reforms are those supported by strong unions rather than those that keep the union role weak.