In addition to being the nation's flagship early education service for at-risk preschoolers, Head Start is clearly the most researched model of widespread early intervention in America. After more than 40 years of implementation, experimentation, and debate, Head Start remains an evolving program (Zigler & Styfco, 2004). As a comprehensive child and family support and early education program, Head Start has continued to respond to the changing conditions of American children and families over the past 4 decades. This includes adaptations of the Head Start model for use with infants and toddlers, which grew out of a renewed appreciation for the importance of prenatal and infant development. Similarly, efforts to create and strengthen collaborations with child care and state agencies were prompted by increased rates of child care attendance and a strengthened role of states in providing prekindergarten services. Much of Head Start's evolution has been informed by research on both child development and program effects. The authors in this special issue on Head Start, including Early Head Start, as an evolving model of early education and family support describe what has been learned about how to best serve children and families, how Head Start as a program has responded to new knowledge from researchers and practitioners, and how research-based policy development may position Head Start for continued responsiveness to the ever-changing needs of children and families.

After decades of research, much is already known about the effectiveness of Head Start. In the lead article by Zaslow, results of the first year of the Head Start Impact Study (U.S. Department of Health and Human Services, 2005) are put into context. As a random-controlled evaluation of a nationally representative sample of Head Start programs, the Head Start Impact Study is the most rigorous and ambitious evaluation of a widespread early education program ever conducted, examining its impacts across an array of child and family outcomes. Highlighting Head Start's historic role as a national laboratory for exploring best practices in early education and family support, Zaslow discusses Head Start's impacts across the range of child development, emphasizing its holistic approach of focusing on all of the areas of child and family development. Zaslow also provides insightful commentary on the challenges of English language learners in Head Start and the apparent benefit of combining Head Start and Early Head Start to provide seamless services throughout all of the years preceding kindergarten entry.

Knitzer continues this discussion of the importance of the first 3 years of life in her article, challenging decision makers to answer science with clear policies that value child development from the prenatal period onward. With science clearly indicating the importance of early development, Early Head Start is still serving less than 3% of the eligible infant-toddler population. This indicates how far we still have to go in creating and implementing a national framework of early support that does not chop childhood--and children--into age ranges in a manner that is artificial and ignores the important preventive impacts that could be realized during the first 3 years of development. Knitzer describes 5 areas in which national policies could lay a firmer foundation for all children, including expanded family leave, increased access to programs for children and families, improved quality of child care for all infants and toddlers, early intervention services for those most in need, and statewide infrastructures for supporting healthy social-emotional development.

Of course, children do not stop developing at kindergarten entry. The gains achieved during Head Start need to be supported throughout elementary school and beyond (Pianta, Cox, & Snow, 2007). Gilliam's article discusses how Head Start's continued evolution may present opportunities to better link the best of what Head Start offers to early educational opportunities in the public schools. Together, Knitzer and Gilliam present a vision of integrated services throughout early childhood, from prenatal into elementary school.

From its inception, Head Start has focused on the "whole child"-stressing the importance of children's cognitive, linguistic, physical, and social-emotional development, their health and mental health, and their functioning within healthy families and healthy communities (Zigler & Trickett, 1978). The "whole child" approach also stresses the importance of understanding each child within the contexts of the home and broader community. Inherent in this holistic approach to child development is an appreciation for each child's, each family's, and each community's unique strengths and how these strengths can be nurtured to promote resiliency. Lamb-Parker and colleagues present 2 systemic mental health approaches that have been used successfully in Head Start programs that embrace this strength-based focus. In addition to focusing on the promotion of resiliency, as opposed to a singular focus on reducing behavioral problems, both of the models presented stress the importance of strong and responsive collaboration among Head Start teachers and staff, ancillary support professionals, and families.

Drawing on Epstein's (1995) 6-factor model of parental involvement, Henrich and Gadaire present recommendations for how Head Start may build on its 2-generational approach to child development by using research-based strategies for improving parents' involvement in their children's education. Challenges to promoting family involvement, such as persistent poverty, mental health barriers, and the lack of significant male role models in the lives of many children, are discussed. Henrich and Gadaire provide several research-based strategies for facilitating increased parental involvement and stronger collaboration between Head Start and children's families and child care providers. Infancy and toddlerhood (the timeframe when Early Head Start services are provided) are optimal periods for facilitating robust parent-child attachment relationships and laying the foundation for healthy home-school collaboration. Condon and Spieker describe an effort to impact these important areas in the context of a University-Early Head Start Partnership program. In the course of describing this collaborative project, the role of researchers as collaborators with Head Start staff is stressed.

This special issue closes with a brief discussion by Britto and Gilliam of how Head Start, with its historical emphasis on a holistic approach, has served as an international model for the development of early childhood programs, drawing contrasts between the rationale of early education as an investment in the United States versus the emerging view of the international community of early education as a fundamental right of all children. After 40 years of development, implementation, research, and debate, it is clear that Head Start has been a success story for many children and families. It is equally clear that much remains to be learned and done if all children are to be given the start they deserve.

At the time that this special issue is going to press, the 110th Congress has passed the Improving Head Start for School Readiness Act of 2007, which is now on its way to the President's desk, where his signature is expected at about the time that this special issue will appear in print. Many of the recommendations made in this special issue appear as components of this reauthorization. The law would retain Head Start's focus on comprehensive services while improving teacher qualifications by mandating that by 2013 at least half of all Head Start teachers will hold a bachelor's degree, providing and funding new training programs for teachers, and focusing program accountability on effective teaching practices rather than the ability of preschoolers to take tests. Added funds will increase the number of children Head Start serves, specifically prioritizing the expansion of Early Head Start to serve more infants and toddlers. Better coordination between Head Start and the public schools and other providers of early childhood services will be enhanced through alignment of Head Start's performance standards with state early learning standards, increased coordination and ability to share resources with state prekindergarten systems and other state agencies, and improved linkages to special education and state health and mental health systems. Although the implementation of these changes may prove challenging, Head Start's greatest strength is its ability to sustain and evolve.

Walter S. Gilliam, PhD

Guest Editor, Yale University

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