At the time of this review, there are no available published research studies on the HighScope Infant-Toddler Curriculum. Rigorous research is needed in order to establish evidence for positive effects of the HighScope Infant-Toddler Curriculum on children's learning outcomes.

Responsive Relationships and Interactions: The curriculum consistently promotes responsive relationships and interactions, which are foundational to children's social and emotional development and development in all other domains. Tender Care and Early Learning describes how to nurture secure attachment relationships with infants and toddlers, including program policies (e.g., continuity of care, primary caregiving) and specific teaching practices (e.g., sensitivity to non-distress, positive regard, lack of negativity, responsiveness to children's communication). The curriculum emphasizes how to engage in sensitive, responsive caregiving and interactions throughout the day. It suggests observing children, responding supportively to children's needs, following their lead, conversing with children in a give-and-take manner, and commenting on their interests and efforts.

Daily Routines as Opportunities for Learning: The curriculum provides clear guidance on how to use daily caregiving routines as a rich opportunity to support children's development and learning in all domains. Tender Care and Early Learning describes how to establish daily schedules and routines that are predictable as well as flexible and individualized based on children's routines at home, natural biological rhythms, and temperament. In addition, Lesson Plans for a Strong Start provides specific examples of how to support and extend children's learning and development during daily routines of "Bodily Care," "Mealtimes," "Transitions," "Drop-off," and "Pick-up" (e.g., learning about attributes, pattern, change, or sequence; developing self-care skills).

Play and Exploration: The curriculum provides extensive guidance on research-based practices to support toddlers' play and exploration. The curriculum offers specific strategies for teachers to create safe and engaging indoor and outdoor environments that promote children's active play and exploration. The curriculum emphasizes providing ample opportunities for child-initiated play and activities based on children's interests, which research shows relates to children's attention, engagement, initiative, and curiosity. Throughout the curriculum, teachers are repeatedly encouraged to allow children to explore the classroom freely, observe children's interests, engage with children on their level, and plan how to further support their explorations. Finally, the curriculum stresses the importance of providing open-ended learning materials and experiences that promote children's curiosity, exploration, and creativity (e.g., building with different types of blocks, playing with fabric scraps or textured balls, exploring metal things).

Language-Rich Environment and Interactions: The curriculum promotes research-based teaching practices to support infants' and toddlers' language and communication. These practices include using varied types of talk and introducing new and interesting vocabulary words based on children's engagement. For example, Tender Care and Early Learning provides general strategies with vignette examples (e.g., make comments, communicate and converse in a give-and-take manner, sing, read). Lesson Plans for a Strong Start integrates suggestions for varied types of talk and vocabulary within learning experiences (e.g., providing names for objects children are touching and using descriptive words such as hard, rough, or fuzzy). Tender Care and Early Learning describes the importance of reading to children and how to select appropriate books for infants and toddlers. Lesson Plans for a Strong Start includes interaction strategies for reading with infants and toddlers (e.g., keeping story groups small, using props from time to time), as well as examples of how to integrate book reading into "Group Times with Materials," "Outside Time," and "Mealtime."

Promoting Emotional, Behavioral, and Cognitive Self-Regulation: The curriculum includes research-based practices to support infants' and toddlers' emotional, behavioral, and cognitive self-regulation. To promote children's emotional and behavioral self-regulation, Tender Care and Early Learning offers guidance on supporting children during social conflicts, providing a soothing physical environment, acknowledging children's feelings and behaviors, and modeling how to cope with feelings. While some of these strategies are integrated throughout Lesson Plans for a Strong Start, others are not. There was also less evidence for other strategies to support children's behavioral regulation, such as redirection of behaviors or providing clear expectations and simple rules for toddlers. The curriculum's lesson plans for toddlers include ongoing scaffolding strategies to support them in developing their executive functioning skills (e.g., acknowledging children's efforts, narrating children's actions and the outcomes of their actions).

Facilitating Cognitive Development: The curriculum promotes some research-based teaching practices to support children's cognition. For example, the curriculum encourages adults to scaffold infants' and toddlers' problem-solving skills by giving children time to try solving their own problems, narrating their actions, acknowledging children's feelings and struggles, and providing assistance as needed. Lesson Plans for a Strong Start provides scaffolding charts for teachers to extend children's learning during play and exploration, such as describing materials, narrating children's actions and explorations, and using open-ended prompts (e.g., "I wonder ...," "What would happen if ..."). Finally, the Lesson Plans for a Strong Start features some learning experiences that focus on introducing toddlers to math language and concepts (e.g., teaching the sign for "more," counting blocks as children play, narrating the sequence of a diaper change). However, there is much less information and emphasis on emergent mathematical thinking in Tender Care and Early Learning or infant Lesson Plans for a Strong Start.

Supporting Physical Development: The curriculum consistently promotes research-based practices to support children's perceptual, motor, and physical development. Lesson Plans for a Strong Start offers many specific learning experiences and scaffolding strategies to support children's gross and fine motor skills (e.g., squeezing squishy bags, grasping and mouthing a shaker, tossing bean bags). In addition, the curriculum emphasizes providing learning environments and experiences to support perceptual understanding and motor development (e.g., providing rich sensory experiences, including various types of surfaces in the physical environment, labeling children's actions). Lastly, the specific suggestions in Lesson Plans for a Strong Start guide teachers to repeat activities as well as to encourage children to practice new skills in different contexts.

Scope: The curriculum clearly identifies six content areas: Approaches to Learning; Social and Emotional Development; Physical Development and Health; Communication, Language, and Literacy; Cognitive Development; and Creative Arts. Tender Care and Early Learning describes each of these developmental domains, and Lesson Plans for a Strong Start provides learning experiences to support children's development in these areas.

Sequence: Tender Care and Early Learning uses the curriculum's key developmental indicators (KDIs) to offer a brief description of children's developmental progressions in each domain. The two Lesson Plans for a Strong Start books each provide 30 days of sample lesson plans, which include multiple related learning opportunities for children to explore or learn concepts and skills in all domains. The lesson plans for activities offer scaffolding charts with specific suggestions for how teachers can support and extend children's learning at earlier, middle, and later developmental levels in all domains. Each scaffolding chart relates to multiple KDIs and provides tips to support children's development in an integrated way. In addition, the curriculum offers strategies and tools to support teachers in future planning of learning experiences based on children's interests and development. While the curriculum provides specific examples for 30 days and general guidance on the process thereafter, the curriculum lacks comprehensive guidance or concrete examples to support children in moving through developmental progressions from birth to 36 months in all domains.

Alignment with the ELOF: A thorough review of all the curriculum materials in relation to the ELOF domains and sub-domains indicates that the HighScope Infant-Toddler Curriculum is mostly aligned with the ELOF. Tender Care and Early Learning and Lesson Plans for a Strong Start provide teaching practices and learning experiences that support children's learning and development in the majority of ELOF sub-domains. However, the curriculum only partially addresses the ELOF sub-domains of Emotional Functioning and Emergent Mathematical Thinking.

Learning Goals: The KDIs are measurable, developmentally appropriate learning goals in all six content areas of the curriculum. KDIs are integrated throughout many of the curriculum's materials, which provide teaching practices and learning experiences to support children's progress toward these goals. The curriculum materials emphasize the importance of using the KDIs to individualize interactions and learning experiences for children and provide specific vignettes to demonstrate how to do it. Furthermore, Lesson Plans for a Strong Start includes scaffolding charts related to multiple KDIs. They offer concrete support for caregivers on how to individualize learning experiences based on children's individual abilities and needs.

Ongoing Observation and Documentation: The HighScope Infant-Toddler Curriculum emphasizes the role of the teacher as an observer throughout all of its materials. It provides guidance on how to observe children as well as strategies for taking daily anecdotal notes, discussing observations with others, and using the information to plan for and scaffold children's learning. In addition, Lesson Plans for a Strong Start includes prompts with information about what teachers should be looking for during a given day (e.g., observing how children communicate with the teacher, verbally or non-verbally, to let the teacher know what they need or want).

Standardized and Structured Assessment Instruments: Tender Care and Early Learning discusses the importance of authentic assessments being valid and reliable, as well as individually, culturally, and linguistically appropriate. The HighScope Infant-Toddler Curriculum encourages programs to use the publisher's Child Observation Record (COR) Advantage.

Communicating with Families: The curriculum provides a range of strategies and materials to foster two-way communication with families. Some of these strategies include home visits, face-to-face interactions at drop-off and pick-up, and creating personal spaces for families in the program. The curriculum includes forms to invite families to share aspects of their culture, values, traditions, hobbies, and daily routines at home (e.g., "All About You!," "Developing an Infant Care Plan Based on Parent Input"). The curriculum suggests that enrollment materials should include photos that reflect the cultural diversity of families in the program. The curriculum also points out several ways culture can affect communication and interactions, such as personal space, smiling, eye contact, silence, and touch. Finally, the curriculum suggests translating materials (e.g., enrollment materials, bulletin board announcements) into languages other than English depending on the linguistic background of families in the community.

Engaging Families: Tender Care and Early Learning provides guidance on how teachers can create a welcoming environment for families and encourage parents to participate in the center. Let's Play and Learn Together offers tips and activities for families to support children's active learning at home (e.g., including toddlers in self-care routines, exploring objects). This book briefly mentions a couple of examples that reference families' cultures (e.g., hosting a cultural potluck, inviting families to do a cooking activity, learning about food names and families' cultures). However, the curriculum lacks additional guidance on how to engage families who speak languages other than English. The curriculum also lacks direction for engaging parents with disabilities or other special needs.

Professional Development: The publisher, HighScope, offers comprehensive standardized initial training and ongoing professional development. Standardized initial training options include two in-person courses: a one-week introduction to the curriculum and a four-week training that covers the five major topics in the "HighScope Infant-Toddler Wheel of Learning:" active learning, adult-child interaction, learning environment, schedule and routines, and assessment. In addition, HighScope delivers ongoing professional development opportunities through a range of in-person trainings, online courses, and certification programs. Finally, HighScope offers customized trainings for programs.

Curriculum Materials to Support Implementation: The HighScope Infant-Toddler Curriculum provides a comprehensive set of materials to support implementation. Tender Care and Early Learning introduces the HighScope approach and provides guidance on engaging in supportive adult-child interactions, setting up the learning environment, and establishing schedules and routines. The two Lesson Plans for a Strong Start books give teachers six weeks of lesson plans for infants and toddlers as well as information on how to continue to make intentional plans for children. The curriculum also provides a video series that can be used as a tool for coaching or professional development to support staff in their ongoing implementation of the curriculum.

• Fidelity Tool: The curriculum offers the Program Quality Assessment (PQA) tool, which can be used to understand how teachers are implementing the HighScope Infant-Toddler Curriculum. This tool measures the quality of four aspects of curriculum implementation: learning environment, schedules and routines, adult-child interactions, and curriculum planning and child observation.

Active Exploration: Active participatory learning is one of the guiding principles of the HighScope Infant-Toddler Curriculum. Guidance on the learning environment invites teachers to provide children with a variety of interesting and open-ended materials to manipulate and explore. The daily schedule includes multiple opportunities for infants and toddlers to move freely and actively explore during "Choice Time," "Group Time with Materials," "Group Time with Music," and "Outdoor Play." For example, a toddler "Group Time with Materials" has teachers offer children different types of tubes to explore and suggests providing additional tubes to support the ways toddlers play with the tubes (e.g., lining up tubes, fitting one inside the other, tapping them on the floor).

Interactions That Extend Children's Learning: Adult scaffolding represents another guiding principle of the HighScope Infant-Toddler Curriculum. The "Supportive Adult-Child Interactions" chapter provides guidance and examples on how teachers can engage in interactions that extend children's exploration, thinking, and communication (e.g., communicating with children in a give-and-take manner, making comments and acknowledgements, encouraging children's choices in exploration and play). Furthermore, the scaffolding charts embedded throughout the Lesson Plans for a Strong Start books offer specific examples of strategies and interactions to support and extend children's learning and development in the various content areas (e.g., describing the materials children are exploring and what the infants around them are doing, commenting on children's efforts to reach, scoot, or lean toward an item they are curious about).

Individualization: The curriculum provides some guidance for how to individualize learning experiences for all children. It describes a process for how to observe children, document their development and interests, reflect, and use this information to plan for individual children. Lesson Plans for a Strong Start recommends teachers use the scaffolding charts to make accommodations for children with disabilities, suspected delays, or other special needs. The "All About You!" form suggests the importance of supporting and celebrating families' cultures in the classroom, but there is no advice on how teachers can integrate this information into learning experiences. Tender Care and Early Learning includes one suggestion to include traditional songs and rhymes from the cultures of children's families. The curriculum lacks comprehensive, in-depth guidance on how to individualize learning experiences for children from diverse cultural backgrounds, children who are DLLs, or children who are learning tribal languages.

Environment: The curriculum provides specific guidance on how to organize indoor and outdoor learning environments that promote children's active learning. Tender Care and Early Learning guides teachers on how to build order and flexibility into the physical space (e.g., creating distinct care and play areas, using moveable furnishings and equipment) and support children's sensory-motor approach to learning (e.g., creating multiple physical levels, providing places for active play and quiet, allowing for stationary play). The Infant-Toddler Learning Environment DVD complements this information with video examples of how to set up and equip the learning environment and includes questions for reflection. Tender Care and Early Learning provides some strategies for how to make the physical environment accessible to children with specific special needs (e.g., how to accommodate wheelchairs, raising or lowering surface heights by shortening table legs or adding sturdy extensions). It also provides a couple of examples of how to include children's culture in the physical environment (e.g., reflecting children's cultures in the house area, adapting the sleep environment for families with differing cultural sleep routines). The curriculum lacks guidance on how to include children's home or tribal languages in the physical environment.

Learning Materials: Many of the curriculum materials provide guidelines and specific examples of developmentally appropriate learning materials that foster open-ended exploration. For example, Tender Care and Early Learning offers lists of specific materials to include in caregiving and play spaces (e.g., push and pull toys, balls, things to fill and empty, dough and clay materials). The Lesson Plans for a Strong Start books specify materials needed for "Group Time with Materials" (e.g., canisters, wooden or metal rings, nesting bowls, scarves). The curriculum provides some suggested materials for children with disabilities or other special needs (e.g., eating utensils with special grips, books with extra-large pictures). However, it includes only a few suggestions on how to select materials that authentically reflect children's cultures and home languages (e.g., providing dolls reflecting racial and ethnic identities of children, providing board books in children's home languages).

Schedule and Routines: Tender Care and Early Learning provides guidance on how to establish a daily schedule that includes arrival and departure, caregiving routines, choice time, outside time, and group time. The curriculum includes multiple tools and a process to support teachers in planning daily schedules centered around individual children's caregiving routines. The curriculum provides extensive guidance on how to support infants' and toddlers' development and learning during caregiving routines. The curriculum emphasizes that daily schedules and routines should be based on individual children's home schedules and natural biological rhythms. It offers the "Developing an Infant Care Plan Based on Parent Input" form to support teachers in gathering information from parents about their children's daily routines and activities at home.

Interactions: The curriculum provides general guidance on how to engage in culturally responsive interactions with families. Tender Care and Early Learning describes how teachers often interact with families from diverse backgrounds (e.g., variety of faiths, cultures, home languages, political beliefs) and offers strategies for teachers to overcome any negative impressions or stereotypes, focus on parents' strengths, and use a problem-solving approach to conflicts. It also points out several ways culture can affect communication and interactions, such as personal space, smiling, eye contact, silence, and touch. Lesson Plans for a Strong Start suggests that teachers conduct home visits to learn more about each family's home life and culture. These books also include the "All About You!" and "Developing an Infant Care Plan Based on Parental Input" forms, which the curriculum suggests help teachers find out more about children's home lives to better support them in the program.

Learning Experiences: The curriculum includes minimal guidance on how to engage infants and toddlers in caregiving routines and learning experiences that build on families' traditions, cultures, values, and beliefs. Lesson Plans for a Strong Start provides the "All About You!" questionnaire for teachers to ask parents about how the classroom can support and celebrate families' cultures, but there is no direction on how teachers can integrate this information into classroom routines and experiences. Tender Care and Early Learning provides one specific example about how to respond to families' values about sleep routines and one prompt for teachers to include traditional songs and rhymes from children's cultures. The curriculum lacks further general guidance or specific examples of how to provide routines and learning experiences that build on children's cultures.

Learning Environment: The curriculum offers general guidance on creating an environment that feels familiar, home-like, and connected to children's personal experiences. It makes a few suggestions for adding materials that reflect children and families from diverse cultures, such as baby dolls reflecting children's racial and ethnic identities, materials in the house area reflecting familiar items to children (e.g., a wok, a rice cooker, a tortilla press), and fabric and material from children's cultures. In addition, the Program Quality Assessment includes indicators that suggest learning materials should depict a wide range of non-stereotyped role models and diverse cultures. However, the curriculum lacks more specific guidance embedded throughout its resources on using materials that authentically represent the cultures and ethnicities of children and families.

Linguistic Responsiveness: The curriculum does not provide guidance on how to intentionally support the development and learning of infants and toddlers who are DLLs or those who are learning tribal languages. The curriculum includes two brief examples of strategies to support children who are DLLs (e.g., using sign language, adding board books in children's home languages), but no information on dual language development or collaborating with families on how to support children's development of each language.

Teaching Practices and Interventions: The curriculum includes some guidance on how to embed teaching practices and other interventions in daily routines and learning experiences to support the development of children with disabilities, suspected delays, or other special needs. Tender Care and Early Learning includes a few examples of teaching practices to support children with disabilities (e.g., using sign language as a communication bridge, accompanying vision-based activities with auditory options for children with impaired vision). Lesson Plans for a Strong Start suggests teachers use the scaffolding charts to provide accommodations for children with disabilities or other special needs. It also suggests choosing and implementing the developmental level that most closely matches the child's current ability. Finally, the curriculum recommends that teachers use Individualized Family Service Plans (IFSPs) and ongoing communication with families to guide plans and strategies to meet the individual needs of children with disabilities, suspected delays, or other special needs.

Learning Environment: Tender Care and Early Learning includes the brief section, "Modifying the Learning Environment to Accommodate Children with Special Needs," which offers general guidance. It includes some specific ideas for adapting materials (e.g., making brush handles and crayons easier to grip by wrapping them with masking tape, pasting fabric shapes into storybooks to make them more tactile) and accommodating wheelchairs (e.g., adding ramps, checking table heights), as well as possible specialized purchases (e.g., eating utensils with special grips, puzzles with knobs). The Lesson Plans for a Strong Start books do not embed specific examples of how to modify the learning environment or materials throughout the lesson plans.

Individualization Based on Interests: The HighScope approach emphasizes the importance of teachers observing in order to plan based on children's interests. Furthermore, "choice" is one of the curriculum's five ingredients for active learning, which allows for children to make choices daily to engage with materials and activities that are of interest to them.

Individualization Based on Strengths and Needs: The HighScope approach emphasizes the importance of teachers observing, planning, and scaffolding based on children's developmental levels. In both Lesson Plans for a Strong Start books, the choice and group time activities include scaffolding strategies to support children at earlier, middle, and later levels of development. In the "Moving Forward" chapter, teachers are reminded to use their ongoing observations to plan for individual children.