Chapter 3: Exploring Early Childhood Education Settings: A Guide to Diverse Learning Environments
Nora Ziburski, EdD
Course Competency: Summarize types of early childhood education settings
Learning Objectives:
- Differentiate between the variety of early childhood education settings
- Differentiate among the unique programming for each stage of development (infant, toddler, preschool, school age)
3.1 Introduction
The type of early childhood education setting a child attends play a crucial role in shaping their development. These settings can range from home-based environments to formal educational institutions, each with its own unique approach to fostering development. This chapter will focus on differentiating between the various types of early childhood education settings and understanding how each program is designed to address the specific needs of infants, toddlers, preschoolers, and school-age children. By examining the distinctive features of each stage, we will gain a deeper understanding of how developmental milestones guide program design and educational practices in early childhood education.
3.2 Settings
Early childhood education settings encompass a variety of environments designed to provide care, learning experiences, and support for young children. These settings can range from home-based programs, such as family childcares, to center-based programs like preschools and childcare centers. Preschools often focus on preparing children for kindergarten by introducing basic academic skills and social-emotional development. Childcare centers provide a broader range of services, including full-time care for infants and toddlers. Additionally, there are specialized programs for children, such as Head Start, which offers comprehensive services for low-income families, and Montessori schools, which emphasize independent learning and exploration (Gordon & Browne, 2017), (Administration for Children & Families, n.d.).
Scenario: Choosing the Perfect Early Childhood Program
The Lee family is expecting their first child and is starting to research early childhood education options. They are overwhelmed by the variety of choices available, from traditional preschools to Montessori schools and home-based daycare.
Peg, the mother, is drawn to the idea of a Montessori school because she appreciates its emphasis on independent learning and exploration. However, her husband, Dave, is concerned about the cost and the potential for long waitlists. They also wonder if a smaller, home-based setting might be a better fit for their newborn.
The Lees decide to visit several different early childhood programs to get a better sense of their options. They tour a local childcare center, a Montessori school, and a family childcare home. At each setting, they observe the interactions between children and teachers, assess the quality of the facilities, and ask questions about the program’s philosophy, curriculum, and costs.
After careful consideration, the Lees decide that a family childcare home is the best option for their family. They find a caregiver who is experienced, caring, and has a good reputation in their community. They believe that a smaller, more intimate setting will provide a nurturing environment for their newborn and allow for more personalized attention.
(Adapted from a Google Gemini created scenario)
Factors That Determine the Type of Early Childhood Program
The type of early childhood program is influenced by several factors, including the following:
- Age Group: Programs are often tailored to specific age groups, such as infants, toddlers, or preschoolers.
- Philosophy: The program’s underlying philosophy, such as Montessori, Reggio Emilia, or traditional, can shape its curriculum and approach.
- Curriculum: The specific educational content and activities offered can vary widely.
- Licensing Requirements: Government regulations and licensing standards can influence the program’s structure and operations.
- Funding: The source of funding, whether public, private, or a combination, can affect the program’s resources and accessibility.
- Location: The program’s location, whether in a home, a school, or a community center, can impact its size and amenities.
- Staff Qualifications: The education and experience of the program’s staff can influence the quality of care provided.
- Family Preferences: Parents’ preferences for their child’s care, such as specific teaching methods or language immersion, can also play a role.
- Special Needs: Programs that cater to children with special needs may have different requirements and accommodations.
These factors can interact in various ways to create a diverse range of early childhood programs that meet the needs of children and families (Gordon & Browne, 2017), (Administration for Children & Families, n.d.), (Workman & Ullrich, 2024).
Types of Early Childhood Education and Childcare Settings
Early childhood education and childcare settings offer a variety of options to cater to families’ needs and preferences. The following subsections describe each type.
Home-Based Settings
- Family Childcare Homes: These are operated by individuals in their own homes, typically caring for a small group of children. They provide a familiar and intimate setting.
- Au Pairs: This arrangement involves a live-in caregiver who provides childcare and companionship for children in exchange for room and board.

Group-Based Settings
- Preschools: Primarily focused on preparing children for kindergarten, preschools offer structured learning experiences, often with a curriculum centered around play and exploration.
- Childcare Centers: These facilities provide full-time or part-time care for children of various ages, from infants to school-aged children. They often offer a wide range of activities and services.
- Head Start: A federally funded program that provides comprehensive services for low-income families, including early childhood education, health screenings, and family support.
- Montessori Schools: These schools follow the Montessori method, which emphasizes independent learning, exploration, and hands-on activities.
- Reggio Emilia Schools: A program with a child-centered approach to early childhood education that emphasizes creativity, collaboration, and documentation.
- Nature-based Preschools: Early childhood education programs that emphasize learning outdoors and connecting with nature. These programs often incorporate natural elements into their curriculum and learning spaces, such as outdoor classrooms, natural materials, hands-on exploration, and a focus on sustainability.

Specialized Settings
- Infant and Toddler Care Centers: Designed specifically for infants and toddlers, these centers provide specialized care and support for young children.
- Early Intervention Programs: For children with developmental delays or differing abilities, these programs offer individualized services to help them reach their full potential.
- Before and After School Programs: These programs provide care and supervision for children before and after school hours.
- Universal Preschools: A system where all children, regardless of family income or background, have access to high-quality preschool education. Often located in public schools through 3-K, 4-K, and 5-K programming.
- Laboratory Schools: Laboratory schools are educational institutions that serve as experimental or demonstration sites for new teaching methods, curriculum, or educational philosophies. These schools are typically affiliated with universities or research institutions, allowing for close collaboration between educators and researchers.
- Employer Sponsored: Employer-sponsored early childhood education programs are childcare programs offered or subsidized by employers for their employees.
- Faith Based Programs: Faith-based early childhood education programs are programs that incorporate religious or spiritual beliefs into their curriculum and practices. These programs often aim to instill moral values, promote spiritual development, and provide a nurturing environment that reflects the values of a particular faith tradition.
- Co-op Preschools: Parent-cooperative preschools involve parents actively participating in the program, often sharing responsibilities like teaching and classroom management.
The best setting for a child depends on various factors, including their age, individual needs, family preferences, and budget. Early childhood professionals should be aware of the various aspects of each program and how it aligns with their own philosophy and career goals.
Type of Program | Definition | Benefits | Challenges |
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Universal Preschool | A system where all children, regardless of family income or background, have access to high-quality preschool education. | Improved school readiness, reduced achievement gaps, and positive economic outcomes. |
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Head Start | A federally funded program that provides comprehensive early childhood education, health, nutrition, and family support services to low-income children and their families. | Helps children develop the skills needed for school success and improves family well-being. |
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Private Preschools | Preschools operated by individuals or organizations, often charging tuition fees. | Wide range of options to meet different family needs and preferences. |
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Montessori Schools | Preschools that follow the Montessori educational philosophy, emphasizing independent learning, exploration, and hands-on activities. | Promotes critical thinking, problem-solving, and social skills. |
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Reggio Emilia Schools | A child-centered approach to early childhood education that emphasizes creativity, collaboration, and documentation. | Fosters children’s curiosity, imagination, and communication skills. |
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Nature-Based Preschools | Preschools that emphasize learning outdoors and connecting with nature. | Improves physical health, cognitive development, and social-emotional skills. |
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Family Childcare Homes | Small-scale childcare programs operated in private homes. | Provides a home-like environment and individualized attention. |
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Head Start
Head Start was launched in 1965 as part of President Lyndon B. Johnson’s War on Poverty. The primary goal was to provide comprehensive early childhood education, health, and nutrition services to low-income children and their families. Initially, Head Start focused on preparing children for school and addressing the social and economic disadvantages faced by many families. Over the years, the program has expanded to include a wider range of services, such as parent education, health screenings, and mental health support. Head Start has been instrumental in improving the lives of millions of children and families, and it continues to be a vital component of early childhood education in the United States.
Head Start programs are considered high-quality early childhood programs for children ages 3-5 due to several key factors. They prioritize child development by providing comprehensive services that address children’s cognitive, social-emotional, and physical needs. Head Start programs typically employ qualified early childhood educators who are trained to implement effective curriculum and support children’s learning. Additionally, these programs often have access to resources and support services that can benefit children and their families, such as health screenings, nutritional support, and special education services. Head Start also emphasizes family engagement, fostering partnerships between parents and educators to create a supportive and nurturing environment for children (U. S. Department of Health and Human Services, Head Start History, n.d.).
Early Head Start
Early Head Start emerged as a natural extension of the Head Start program that was established in 1965. Recognizing the critical importance of early intervention for children from low-income families, Early Head Start was launched in 1995 to provide comprehensive services for infants and toddlers. This program aims to promote children’s healthy development, support parents, and strengthen families. Early Head Start centers offer a range of services, including childcare, health screenings, parent education, and home visits. By providing these resources, Early Head Start seeks to give young children a strong foundation for future success.
A typical day in an Early Head Start program is designed to provide a nurturing and stimulating environment for infants and toddlers (children under 3). The day often begins with children arriving and greeting their caregivers. Activities throughout the day might include free play, group time, story time, outdoor play, meals, and naps. Caregivers are attentive to each child’s needs, providing individualized attention and support. The program emphasizes social-emotional development, language skills, and physical activity. Throughout the day, children are encouraged to explore, learn, and interact with their peers and caregivers in a safe and supportive setting (U.S. Department of Health and Human Services, About the Early Head Start, 2024), (Brunton, 2019).
Migrant and Seasonal Head Start (MSHS) programs are specifically designed to meet the unique needs of children from migrant and seasonal farmworker families. These programs differ from traditional Head Start programs by providing full-day, full-week services—often from 6 a.m. to 6 p.m., six days a week—to accommodate the demanding schedules of agricultural labor. Operating primarily from May to October in many states, MSHS programs serve children from birth to age six, offering a safe and nurturing environment while their families work in the fields. Since 1969, MSHS has supported migrant families, and in 1999, services expanded to include seasonal farmworker families. These programs are vital in communities where local childcare options are limited or unavailable during peak agricultural seasons. Without them, many parents would have no option but to bring their children to the fields, where they could be exposed to harmful conditions such as pesticides, dangerous equipment, and extreme weather. MSHS ensures that these children receive high-quality early learning opportunities in a safe and supportive setting, no matter where their families may travel for work.
Preschools
Preschools in the United States have a rich history dating back to the 19th century. Early forms of preschool education emerged as part of social reform movements, aiming to provide care and education for children from disadvantaged backgrounds. Kindergarten, introduced in the mid-19th century, was one of the earliest forms of preschool education in the U.S. However, it was not until the 20th century that preschools became more widespread and accessible. The Great Depression led to an increase in the need for childcare, and the federal government began to provide funding for nursery schools and other early childhood programs. Since then, preschool education has continued to evolve, with a growing emphasis on preparing children for school success and promoting their social-emotional development. Preschools are often partial day programs lasting from two hours to half a day.
Preschools play a crucial role in supporting early childhood education and child development for children 2-5. They provide a safe and nurturing environment where children can learn and grow at their own pace. Preschools offer a variety of activities that promote children’s cognitive, social-emotional, and physical development, such as art projects, music exploration, outdoor play, and literacy activities. By fostering a love of learning and building essential skills, preschools prepare children for kindergarten and lay the foundation for future academic success. Additionally, preschools can help to bridge the gap between home and school, providing families with support and resources to enhance their child’s learning and development (Michel, 2011).
Family Childcare
Family childcare in the United States has a long and rich history, dating back to the early 20th century. As industrialization led to more women entering the workforce, the need for childcare options increased. Home-based childcare arrangements became a popular solution, providing a familiar and comfortable setting for children. While family childcare has evolved over the years, it remains a significant part of the early childhood education landscape. Today, family child care providers offer a variety of services, catering to different family needs and preferences. They often provide a more personalized and intimate experience compared to larger childcare centers, making them a desirable option for many families.
Caregivers in family childcare settings can tailor their approach to individual children’s needs and interests, fostering a strong sense of belonging and security. Additionally, family childcare can offer greater flexibility for families, with options for part-time care or extended hours. By providing a supportive and familiar setting, family childcare can help children develop essential social, emotional, and cognitive skills while also easing the transition to school (Administration for Children & Families, Family Child Care Homes, n.d.).
Universal Preschool
Universal preschool is a relatively recent development in the United States, gaining significant attention in the early 21st century. The concept of providing free, high-quality preschool education to all children, regardless of their family’s income or background, has gained momentum due to increasing research on the benefits of early childhood education. While there have been some pilot programs and initiatives in various states, universal preschool remains a goal for many advocates and policymakers. The push for universal preschool is often driven by the belief that it can help close educational achievement gaps, improve school readiness, and boost economic growth.
Universal preschool offers several potential benefits, including improved school readiness, reduced achievement gaps, increased workforce participation, and positive economic outcomes. However, implementing universal preschool also presents some challenges. One major concern is the cost, as it requires significant investment in infrastructure, staffing, and curriculum development. Additionally, there are concerns about quality assurance, ensuring that all programs meet the high standards for high-quality play based early childhood education. Another consideration is the potential impact on existing early childhood programs, as universal preschool could affect enrollment and funding for other options. Despite these challenges, many advocates argue that the long-term benefits of universal preschool outweigh the costs and that it is a worthwhile investment in the future of our children (Alliance for Early Success, 2024), (Schoof & Koenig, 2022).
Group Centers (Private Childcare)
Childcare centers in the United States have a long history, dating back to the early 20th century. As more women entered the workforce during the Industrial Revolution, the need for reliable childcare options increased. Early childcare centers were often established in connection with factories or other workplaces, providing care for the children of working mothers. Over time, childcare centers evolved to become more specialized and focused on providing educational and developmental experiences for children. The federal government began to play a role in supporting childcare during the Great Depression, with programs like the Works Progress Administration establishing nursery schools. Since then, childcare centers have continued to grow and diversify, offering a range of services and catering to different family needs.
Childcare centers play a vital role in supporting early childhood education and child development. They provide a safe and nurturing environment where children can learn and grow alongside their peers. Childcare centers often offer a variety of activities and experiences, such as art projects, music classes, outdoor play, and literacy activities. These programs promote children’s cognitive, social-emotional, and physical development, preparing them for future learning and success. Additionally, childcare centers can provide support and resources for families, such as parent-teacher conferences, health screenings, and referrals to community services. By offering a high-quality early childhood education experience, childcare centers can help children develop a strong foundation for lifelong learning and success.
3.3 Programming for Each Stage of Development
Early childhood education and childcare settings must consider different factors for infants, toddlers, and preschoolers due to their distinct developmental stages. Infants require a high level of physical care, including feeding, diapering, and soothing. They are also developing basic motor skills and sensory awareness. Toddlers are more mobile and independent, exploring their environment and learning language skills rapidly. They need a safe and stimulating environment that encourages their curiosity and creativity. Preschoolers are capable of more complex tasks and social interactions. They benefit from programs that promote academic readiness through play, social-emotional development, and language skills. For school-age children, programming should provide a safe, engaging environment that supports their growing independence, offering homework help, opportunities to pursue interests in areas such as sports, arts, and games, and space to build and maintain friendships. By understanding these developmental differences, early childhood programs can provide age-appropriate care and support for children at each stage of their development.
Infant Care (Under 1 year Old)
Infant childcare options provide a safe and nurturing environment for babies while parents are working or attending to other responsibilities. These options can vary widely, from home-based childcare to specialized infant care centers. High-quality infant childcare programs are designed to provide a safe, nurturing, and stimulating environment for babies. They have qualified staff who are trained in infant development and can provide appropriate care and support. These programs offer a variety of activities that promote infants’ physical, cognitive, social-emotional, and language development, such as tummy time, sensory play, and interactive reading. Additionally, high-quality infant childcare programs emphasize communication and collaboration with parents, providing regular updates and opportunities for feedback. The goal of these programs is to help infants develop a strong foundation for future learning and growth (National Association for the Education of Young Children, High-quality Program for Infants, n.d.).

Toddler Care (1-2 years Old)
Toddler childcare options offer a stimulating and supportive environment for young children as they develop new skills and explore their surroundings. These options can include childcare centers, family childcare, and nanny or au pair arrangements. High-quality toddler programs prioritize creating a safe, nurturing, and stimulating environment for young children. They have qualified staff who understand toddler development and can provide appropriate care and guidance. The programs offer a variety of activities that support toddlers’ physical, cognitive, social-emotional, and language development. These activities may include art projects, music experiences, outdoor play, and story time. Additionally, high-quality toddler programs emphasize communication and collaboration with parents, providing regular updates and opportunities for feedback. The goal of these programs is to help toddlers develop a strong foundation for future learning and growth (National Association for the Education of Young Children, High-quality Toddler Program, n.d.), (National Association for the Education of Young Children, High-quality Program for Toddlers Look Like?, n.d.).

Preschool Care (3-5 years Old)
Preschool education and childcare options offer a variety of programs to prepare young children for kindergarten and beyond. These options can include preschools, childcare centers, and family childcare. Preschools often focus on academic readiness, social-emotional development, and language skills. When choosing a preschool or childcare option, parents should consider factors such as the program’s philosophy, the quality of care provided, and the overall fit with their child’s individual needs and family’s lifestyle.

High-quality preschool programs are characterized by several key features. They typically have a well-defined curriculum that promotes children’s cognitive, social-emotional, and physical development. The programs are staffed by qualified early childhood educators who provide nurturing and supportive care. Classrooms are designed to be safe, stimulating, and age appropriate. High-quality programs also prioritize parent involvement, fostering partnerships between families and educators. Additionally, these programs often have access to resources and support services that can benefit children and their families, such as health screenings, nutritional support, and special education services (National Association for the Education of Young Children, High-quality Program Preschooler Program, n.d.).
School-age Childcare (Kindergarten – 5th Grade)
School-aged childcare programs offer a safe and supervised environment for children when school is not in session. These programs can be found in schools, community centers, or private businesses. They often provide a variety of activities, such as homework help, arts and crafts, sports, and games. School-aged childcare is a valuable resource for working parents or families who need extra support.
![Google AI. Gemini. (2025). Flash 2.0. [Artificial intelligence system]. https://gemini.google.com/ Several children are sitting at small tables while their teacher is instructing them in an activity](https://wtcs.pressbooks.pub/app/uploads/sites/67/2025/03/unnamed-4.png)
School-aged childcare options vary widely to meet different family needs. Some programs are operated by schools themselves, while others are offered by community centers or private businesses. There are specialized programs for children with special needs, as well as those offering before and after-school care or full-day care during school breaks. Additionally, transportation to and from school may be available. This variety allows families to choose the program that best suits their child and their lifestyle (Administration for Children & Families, School-age Childcare and Camp Programs, n.d.).
Now that you have an understanding of the various early childhood and school-age care settings—as well as the unique developmental needs of infants, toddlers, preschoolers, and school-aged children—it’s important to know how to recognize high-quality care in each environment. One helpful way to do this is by using a checklist that highlights key indicators of quality. This checklist can guide you in observing and evaluating how well a program supports children’s health, safety, learning, and relationships. Let’s take a closer look at the elements that define a high-quality early care and education setting.
Checklist for High-Quality Early Childhood Education Programs | |
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Physical Environment |
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Curriculum and Instruction |
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Family Engagement |
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Health and Safety |
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Program Philosophy |
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Program Evaluation |
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By considering these factors, you can evaluate the quality of an early childhood education program.
Reflect
Consider these questions as you think about what type of early childhood setting in which you would like to work:
- What type of curriculum or teaching philosophy aligns with your values and beliefs? (e.g., Montessori, Reggio Emilia, traditional)
- Do you prefer a more child-centered or teacher-directed approach?
- Are you interested in a program with a specific focus, such as nature-based, bilingual, or special needs education?
Scenario: Choosing the Right Preschool
Imagine you’re a parent trying to decide which preschool is the best fit for your child. What are some important qualities you should look for in a preschool program?
Here are some questions to consider:
- What are the most important qualities you would look for in a preschool program?
- How would you evaluate the quality of the teaching staff?
- What factors would influence your decision regarding the curriculum and activities offered?
- How important is the physical environment of the preschool?
- What role do you think parents should play in their child’s early childhood education?
Share your thoughts on what makes a high-quality preschool program.
Learning Activity 1
Learning Activity 2
3.4 References
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Administration for Children & Families. (n.d.). School-age childcare and camp programs. ChildCare.gov. https://childcare.gov/consumer-education/school-age-child-care#:~:text=School%2Dage%20programs%2C%20also%20known,schedule%20and%20school%20year%20calendar
Alliance for Early Success. (2024). What is universal pre-K? https://earlysuccess.org/what-is-universal-pre-k/
Brunton, R. (2019). Research: Early head start improves outcomes for children and families. ZERO TO THREE. https://www.zerotothree.org/resource/research-early-head-start-improves-outcomes-for-children-and-families/
Google AI. Gemini. (October 2024 version). [Large language model]. https://gemini.google.com/
Gordon, A. M., & Browne, K. W. (2017). Beginnings & beyond: Foundations in early childhood education (10th ed.). Cengage Learning.
Haigh, K. (2009). An approach for all children: Reinterpreting the Reggio Emilia approach in the USA. Community Playthings. https://www.communityplaythings.com/resources/articles/reinterpreting-the-reggio-emilia-approach-in-the-usa-an-approach-for-all-children
Maria Montessori Training Organization. (2024). What is Montessori? Maria Montessori Institute. https://www.mariamontessori.org/about-us/what-is-montessori/
Michel, S. (2011). History of childcare in the U.S. VCU Libraries Social Welfare History Project. https://socialwelfare.library.vcu.edu/programs/child-care-the-american-history/
NAEYC. (2019). Defining and recognizing high-quality early learning programs: NAEYC’s 10 accreditation standards. Teaching Young Children, 13(1). https://www.naeyc.org/defining-recognizing-high-quality-early-learning-programs
National Association for the Education of Young Children. (n.d.). A high-quality program for your toddler. NAEYC. https://www.naeyc.org/our-work/families/high-quality-program-for-toddler
National Association for the Education of Young Children. (n.d.). A high-quality program for your preschooler. NAEYC. https://www.naeyc.org/our-work/families/high-quality-program-for-preschooler
National Association for the Education of Young Children. (n.d.). What does a high-quality program for infants look like? NAEYC. https://www.naeyc.org/our-work/families/high-quality-program-for-infant
National Association for the Education of Young Children. (n.d.). What does a high-quality program for toddlers look like? NAEYC. https://www.naeyc.org/our-work/families/what-does-high-quality-program-for-toddler-look-like
National Association for the Education of Young Children. (n.d.). What to look for in a program. NAEYC.org. https://www.naeyc.org/our-work/families/what-look-program
National Association for the Education of Young Children. (n.d.). What you want to see in a high-quality infant program. NAEYC. https://www.naeyc.org/our-work/families/what-you-want-to-see-infant-program
North American Association for Environmental Education (NAAEE). (2023). Nature preschools in the United States: 2022 national survey [PDF]. Natural Start. https://naturalstart.org/sites/default/files/staff/natstart_2022_national_survey_final_draft.pdf
Reggio Emilia Approach. (2022). Reggio children. https://www.reggiochildren.it/en/reggio-emilia-approach/
Schoof, J., & Koenig, B. (2022). Universal pre-K would block innovation, harm children. The Heritage Foundation. https://www.heritage.org/education/commentary/universal-pre-k-would-block-innovation-harm-children
U.S. Department of Health and Human Services (HHS). (2024). About the early Head Start program. https://headstart.gov/programs/article/about-early-head-start-program?redirect=eclkc
U.S. Department of Health and Human Services (HHS). (n.d.). About the office of Head Start. HeadStart.gov. https://eclkc.ohs.acf.hhs.gov/about-us/article/office-head-start-ohs
U.S. Department of Health and Human Services (HHS). (n.d.). Head Start history. The Administration for Children and Families. https://www.acf.hhs.gov/ohs/about/history-head-start
Whitaker, R. C., Becker, B. D., Herman, A. N., & Gooze, R. A. (2013). The physical and mental health of Head Start staff: The Pennsylvania Head Start staff wellness survey, 2012. Preventing Chronic Disease, 10, E181. https://doi.org/10.5888/pcd10.130171
Workman, S., & Ullrich, R. (2024). Quality 101: Identifying the core components of a high-quality early childhood program. americanprogress.org. https://www.americanprogress.org/article/quality-101-identifying-the-core-components-of-a-high-quality-early-childhood-program/
Images:
Figure 3a: “IMG_2791” by Nora Zubriski is licensed under CC BY-NC 4.0
Figure 3b: “IMG-0835” by Nora Zubriski is licensed under CC BY-NC 4.0
Figure 3c: “USMC-13222.jpg” by unknown author for U.S. Marines is in the Public Domain. The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement.
Figure 3d: “IMG_6958” by Nora Ziburski is licensed under CC BY-NC 4.0
Figure 3e: Google AI. Gemini. (2025). Flash 2.0. [Artificial intelligence system]. https://gemini.google.com/
Figure 3f: Google AI. Gemini. (2025). Flash 2.0. [Artificial intelligence system]. https://gemini.google.com/