At the time of this review, there are no research studies on the Core Knowledge® Preschool Sequence (Core Knowledge®) available in peer-reviewed journals. The publisher presents two studies with Core Knowledge® on their website. In these studies, children made gains in language, literacy, and mathematics outcomes. However, both studies used a pre-/post-test design with no comparison group. More rigorous research is needed in order to establish evidence for the effect of Core Knowledge® on children's positive learning outcomes.

Approaches to Learning: Core Knowledge® promotes some research-based teaching practices to support children's approaches to learning, such as promoting sensitive, responsive caregiving. The curriculum also includes guidance on classroom organization (e.g., sample schedules, descriptions of learning centers and materials) and classroom management strategies (e.g., brainstorming and creating rules with children, providing visual cues), which promote executive functioning skills. The daily schedule includes learning centers where children can participate in activities based on their interests and engage in child-initiated play that promotes open-ended exploration. However, the curriculum provides fewer strategies and activities that support children in developing emotional and behavioral regulation.

Social and Emotional Development: Core Knowledge® promotes a few research-based teaching practices in this domain. The curriculum provides guidance on how to establish an emotionally supportive environment and suggestions on how to build secure, trusting adult-child relationships. For example, scaffolding strategies embedded in the "Teacher Responses" and "Teacher Feedback" sections of the Core Knowledge Preschool Sequence and Teacher Handbook (Handbook) emphasize how to engage in sensitive and responsive interactions. The "Autonomy, Social Skills and Work Habits" chapter guides teachers to identify and label emotions, and there is reference to the Stop and Think Social Skills Program. However, there is limited evidence that the curriculum supports teachers to use language intentionally to foster children's social and emotional development, or that it encourages teachers to coach and guide children to use problem-solving skills to resolve conflicts. References to culturally and linguistically responsive practices are minimal.

Language and Communication: Core Knowledge® consistently promotes research-based teaching practices in this domain, such as providing guidance on how to create rich oral language experiences and opportunities to hear, use, and understand complex language. For example, the Handbook section "Language of Instruction" includes a sampling of precise vocabulary for each chapter. The curriculum also provides learning experiences using the sounds of language to develop phonological awareness through nursery rhymes, poems, fingerplays, and songs.

Literacy: Core Knowledge® consistently promotes research-based teaching practices to support children's literacy development. For example, it provides varied opportunities for children to discuss, use, and make print materials (e.g., using print during daily routines, creating charts with children). Guidance for storybook reading and storytelling, such as the STORY and INFO techniques, engages children as active participants. The curriculum suggests learning experiences that include varied, meaningful opportunities to develop emergent writing skills; teachers are encouraged to model and support children's writing activities across all play experiences (e.g., writing lists, signs, recipes). Furthermore, the curriculum provides strategies for interactive read-alouds that include opportunities for children to develop concepts about print, alphabet knowledge, and comprehension skills, which research shows are critical early literacy skills. Even so, the curriculum lacks guidance on how to plan literacy experiences based on rich and engaging content.

Mathematics Development: The curriculum promotes some research-based teaching practices to support children's mathematics development. "Teaching Ideas" and "Cross-Curricular Connections" provide suggestions for learning experiences and strategies to promote conceptual understanding, develop procedural skills, and introduce children to the language of mathematics. For example, one "Teaching Idea" suggests using hula hoops to create a Venn diagram to visually depict sorting and classifying objects according to two attributes. While the curriculum presents a developmental sequence of math skills, it is unclear how "Teaching Ideas" and "Cross-Curricular Connections" are sequenced based on children's development. In addition, most of the suggested learning experiences are skill-focused. Thus, children have limited opportunities to engage in problem-solving, inquiry, and creative invention.

Scientific Reasoning: Core Knowledge® promotes some research-based teaching practices in this domain, such as guiding teachers to support the development of important inquiry skills. For example, the Handbook provides specific guidance for engaging children in the scientific reasoning cycle (reflect and ask, plan and predict, act and observe, and report and reflect). "Creating an Engaging Science Center" describes how teachers set up, introduce, and interact with children in the science center. Guidance explains how teachers can use specific science language (e.g., hypothesize, describe). The "Teaching Ideas" and "Cross-Curricular Connections" provide suggestions for science learning experiences. However, the curriculum does not provide specific guidance on how to embed science in daily activities and play. It also lacks opportunities for children to explore scientific concepts in depth through multiple, varied, conceptually related learning experiences.

Perceptual, Motor, and Physical Development: The curriculum promotes a few research-based teaching practices to support children's perceptual, motor, and physical development. It provides some guidance on intentional teaching practices to support the development of physical skills and perceptual motor development. For example, the Handbook includes "Teaching Ideas" that incorporate specific instructions and targeted learning goals (e.g., have children throw rolled socks into shoe boxes). However, the curriculum lacks consistent guidance on how to use intentional teaching practices to support the development of self-care skills and personal safety knowledge. In addition, the curriculum lacks guidance on creating a safe outdoor environment that encourages physical activities.

Scope: Core Knowledge® clearly identifies five developmental areas: Approaches to Learning, Social and Emotional Development, Language and Literacy Development, Knowledge and Cognitive Development, and Physical Well-Being and Motor Development. The Handbook subdivides the developmental areas into domains/content areas (e.g., under Language and Literacy, one of the domain/content areas is Oral Language) and includes a chapter that lists the Preschool Sequence skills for each domain/content area. Each chapter provides a brief description of what teachers should know, scaffolding suggestions, and some "Teaching Ideas" to support children's development for domain/content areas.

Sequence: A thorough review of the curriculum materials indicates that Core Knowledge® includes competencies and skills for each domain that are listed sequentially (from less to more complex). The curriculum also provides "Sample Year-Long Curriculum Plan," which maps the skills of the Preschool Sequence to each month of the school year. However, it is unclear how the sequence of skills is mapped to suggested learning experiences. Core Knowledge® does not provide a defined set of learning experiences, but rather a limited number of examples and suggested activities (e.g., "Teaching Ideas," "Cross-Curricular Connections") to illustrate how skills in each content area may be supported. These do not build from less to more complex to support children as they move through the developmental progressions, nor do they provide multiple, related opportunities to explore a concept or skill with increasing depth.

Alignment with the ELOF: A thorough review of all of the curriculum materials in relationship to the Head Start Early Learning Outcomes Framework (ELOF) domains and sub-domains indicates that Core Knowledge® is minimally aligned with the ELOF. The Handbook includes some "Teaching Ideas" and "Cross-Curricular Connections" that briefly describe learning activities that support children's development in each of the ELOF domains. While all seven domains are addressed, a large number of sub-domains are partially addressed, including Emotional and Behavioral Self-Regulation; Cognitive Self-Regulation; Emotional Functioning; Sense of Identity and Belonging; and Health, Safety, and Nutrition.

Learning Goals: The curriculum specifies learning goals and specific skills for each goal within content area chapters of the Handbook. The skills are presented in order of difficulty, with easier skills preceding more complex ones. Most of the learning goals are measurable; and while many are developmentally appropriate, some goals are too advanced for preschool children (e.g., distinguish objects of the more "recent past" from objects of the "distant past;" use a simplified, illustrated telephone listing). Overall, the "Teaching Ideas" and "Cross-Curricular Connections" would support children in making progress toward the learning goals within each content area. However, the learning goals are not explicitly integrated or connected with these learning experiences. In addition, the curriculum lacks guidance on how to use the learning goals to individualize learning experiences for all children.

Ongoing Observation and Documentation: The Handbook provides general guidance about how teachers can observe children's development and learning across the daily routine. The curriculum explains that teachers can use observations, collections of children's work samples, and activity probes (performance-based assessments) to understand children's developmental progress over time. While it offers specific information in sections called "What to Look For" and "When to Look," the curriculum lacks guidance on how to document observations. Moreover, little information is provided on how to use assessment information to plan instruction.

Standardized and Structured Assessment Instruments: The Handbook describes the importance of valid, reliable assessment. The Core Knowledge® Preschool Assessment Kit and Core Knowledge® Preschool Assessment Tool are available for purchase at an additional cost. The curriculum does not address the importance of using individually, culturally, and linguistically appropriate assessment instruments.

Communicating with Families: The Handbook includes some strategies for sharing information with families (e.g., monthly newsletter, regular parent meetings). While the curriculum describes the importance of recognizing parents as sources of information about the child and family, it lacks guidance on how to learn from families about their child's development, culture, home language, and background. The curriculum includes some considerations and strategies for working with culturally and linguistically diverse families. For example, the curriculum cautions teachers not to overwhelm families with educational jargon, to keep wording simple, and to use plenty of visual support in activity directions.

Engaging Families: The Handbook describes the importance of engaging parents and families in children's learning and development, and it offers general guidance on how to do so. Some strategies include implementing an open-door policy, conducting special events (e.g., monthly family nights and school celebrations), and creating weekly home learning activities. Activity books for families are available at an additional cost. However, the Handbook lacks guidance on how to use them with families. There is no guidance on how to engage parents with disabilities or other special needs.

Professional Development: Core Knowledge® offers multiple options for standardized initial training. Examples include a two-day "Leadership Institute" and "Getting Started with the Preschool Sequence." The curriculum offers ongoing professional development and training through "turnkey professional development kits," on-site training, and annual conferences. These opportunities include a range of topics, such as supporting language development or assessment and planning to meet children's needs. Additionally, sites may request diagnostic visits and plan individualized supports based on their needs.

Curriculum Materials to Support Implementation: Core Knowledge® provides materials to support implementation, including the Handbook and the Core Knowledge® P-8 Implementation Resources Guide (available online). The Handbook includes general information on lesson planning, classroom environment, routines, and teaching practices. However, it lacks sufficient information about learning experiences.

• Fidelity Tool: Core Knowledge® includes Snapshot: Implementation and Observation Checklists, a fidelity tool for monitoring curriculum implementation. The tool addresses areas such as classroom environment, classroom practices, and daily routines. While the "Getting Started with the Preschool Sequence" professional development kit introduces the fidelity tool, it is not referenced within the Handbook.

Active Exploration: Core Knowledge® promotes active exploration and children have opportunities to initiate activities and explore newly introduced skills and concepts during center time (e.g., science, math, and art areas). However, there is little guidance on how center time can be used to support active exploration. For example, little guidance is offered on the kinds of materials that should be used in the centers or how the learning centers can be used to foster active exploration. Some of the "Teaching Ideas" limit children's active exploration during center time. For example, the curriculum provides specific directions on how to engage children with materials in the sensory table.

Interactions that Extend Children's Learning: The curriculum provides guidance on how to use interactions to extend children's learning. For example, the "Using Language to Think" section of the Handbook provides guidance on how to encourage children to predict and analyze qualities of objects. In addition, the "Oral Language" chapter includes guidance on using self- and parallel-talk as well as open-ended questions to extend children's learning.

Individualization: The curriculum provides general guidance on how to ensure learning experiences are accessible and appropriate for all children. It provides specific strategies for scaffolding the learning of children who need "higher and lower degrees of support." Additionally, the "English Language Learners" chapter includes information about the stages of second language acquisition and "language support strategies" for each stage. The Handbook lacks guidance on how to authentically incorporate children's languages and cultures throughout learning activities or learning centers. Though the Handbook states that various elements of the Preschool Sequence lend themselves to supporting an inclusive classroom, the curriculum lacks guidance on how to individualize learning experiences for children with disabilities, suspected delays, or other special needs.

Environment: The curriculum provides general guidelines on how to design well-organized, engaging indoor environments. It provides considerations on how to enhance children's use of space, strategies for incorporating learning centers, and ways to arrange the physical environment to support classroom management. The Handbook offers additional guidance for ensuring the environment is welcoming, as well as print- and math-rich. The curriculum lacks guidance on how to set up the outdoor learning environment. Furthermore, it does not address how to include children's cultures or home languages in the physical environment.

Learning Materials: Core Knowledge® provides a limited number of materials, including Social Skills Posters, Pictorial Schedule Cards, and the Stop and Think Social Skills CD. The Handbook provides suggestions for specific learning materials (e.g., manipulatives, books, measuring tools) to be used in specific activities ("Teaching Ideas") and learning centers. The curriculum mentions that effective teachers ensure classroom materials include some items in the child's home language but lacks further guidance on what materials should be included or how to select them. While the curriculum notes materials may need to be adapted for children with disabilities, suspected delays, or other special needs, it provides minimal guidance on how to ensure that learning materials are accessible. Finally, the curriculum lacks guidance on how to select and provide materials that authentically represent the cultures and ethnicities of the children.

Schedule and Routines: The curriculum includes specific guidance on how to establish a developmentally appropriate daily schedule. It offers sample schedules for half- and full-day programs and descriptions of what occurs during each part of the schedule (e.g., circle time, meals). However, the curriculum lacks guidance on how to individualize schedules or routines based on individual children's needs and backgrounds.

Interactions: The curriculum provides some general considerations for working with culturally and linguistically diverse families and children. For example, the Handbook explains that there may be cultural differences related to parent involvement or communication styles. However, the curriculum lacks specific guidance on how to engage in culturally responsive interactions with children and families.

Learning Experiences: Core Knowledge® does not offer any guidance on how to provide learning experiences that build on children's and families' traditions, cultures, values, and beliefs. Rather, the approach is to help all children learn the same content, regardless of their family and economic background.

Learning Environment: The curriculum provides minimal guidance on how to use learning materials that authentically represent the cultures and ethnicities of children and families. The Handbook suggests stories "include content related to the cultures of English language learners." The curriculum lacks guidance on how to select learning materials that represent the cultures and ethnicities of children and families in the program.

Scaffolding Strategies: The Handbook provides general guidance on teaching children who are DLLs (e.g., making cross-curricular connections, offering visuals, allowing home language to be used to demonstrate understanding). In addition, the curriculum includes information about the stages of language acquisition and some language support strategies for each stage.

Home and Tribal Languages: Core Knowledge® lacks guidance on how to incorporate children's home languages into the learning experiences and environment. Tribal languages are not addressed.

Teaching Practices and Interventions: The Handbook provides general strategies for using the curriculum with children who have disabilities, suspected delays, or other special needs (e.g., using visuals, differentiating instruction). However, the curriculum lacks guidance on how to embed specific research-based teacher practices or other interventions in daily routines and activities.

Learning Environment: The curriculum provides general guidance on how to ensure learning materials and the physical space are accessible for children with disabilities, suspected delays, or other special needs. The Handbook includes a few specific adaptations (e.g., adjusting the physical environment to accommodate wheelchair access, using visuals to help children with autism follow directions). However, universal design principles are not discussed. The Handbook does not provide consistent, embedded guidance on how to ensure the physical environment and learning materials are accessible to all children.

Individualization Based on Interests: The Handbook discusses the importance of child-initiated activities and provides some information about following children's interests during informal conversations and learning center time. However, the curriculum does not provide guidance on how to plan learning experiences that build on individual children's interests.

Individualization Based on Strengths and Needs: The Handbook provides general guidance on how to make learning experiences responsive to individual children's strengths and needs. For each domain, the curriculum includes examples of scaffolding for children who need higher and lower levels of support. It states, "Although the examples below demonstrate only high support and low support, effective teachers adjust support along the continuum to meet the needs of individual children."