This report is an evaluation of the National Early Years Access Initiative (NEYAI), a three-year programme (2011-2014) to improve quality and outcomes in the early years sector. NEYAI comprises 11 projects mainly located in disadvantaged areas of Dublin, Cork and Limerick and two rural locations in Longford/Westmeath and Donegal. It was officially launched by the Minister for Children & Youth Affairs in June 2011 who referred to NEYAI as being made up of local demonstration projects with 'a focus on evidence-based practice and ongoing project evaluation for the purpose of advising future policy and the mainstream provision'. A substantial body of evidence has been created through NEYAI including this Summary Report and the Main Report and Technical Report on which it is based; reports from local evaluations in each NEYAI project; and an evaluation of the NEYAI Learning Community. Details of the 11 NEYAI projects are in Appendix One while contributors to this report, including the funders of NEYAI, are acknowledged in Appendix Two. NEYAI projects are multi-dimensional in their activities, implementing multiple programmes (such as staff training and mentoring, parenting courses, family support services, interagency collaborations), across multiple sites, with all age-ranges of children from birth to six, and including their parents. This diversity of activity, much of it unique to each project, created challenges for the national evaluation because it was necessary to find a common theme across all projects which would allow a coherent and systematic approach to the evaluation. In response to these challenges, the evaluation focused on one age-group of children, namely those attending the 2012/13 Free Pre-School Year, and compared child outcomes in NEYAI with those in the Siolta Quality Assurance Programme (Siolta QAP). Siolta QAP is a 12-step quality improvement process for early years centres; it is supported by mentors with progress and validation based on a portfolio to demonstrate that Siolta standards are being met in each centre. The rationale for this research design is that NEYAI and Siolta QAP both share the same broad aim of improving quality in the early years sector while Siolta QAP occurred earlier and lasted longer than NEYAI (at least longer than the intervention period of the NEYAI evaluation) thereby providing a validated standard or benchmark of quality. (author abstract)