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

Responsive Relationships and Interactions: Frog Street Toddler offers suggestions for how to build secure, trusting adult-child relationships that are foundational to children's development in the Social and Emotional domain and all other domains. For example, Welcome to Frog Street Toddler recommends assigning primary caregivers. The Activity Guides invite caregivers to spend time engaging with children and showing physical affection. The curriculum mentions the importance of being responsive to children's cues and needs, but it lacks comprehensive guidance on how to engage in sensitive, responsive caregiving with toddlers. The curriculum offers many opportunities for teachers to initiate joint attention with toddlers. However, it gives minimal guidance to teachers on how to start a back-and-forth exchange based on the child's focus or interest.

Daily Routines as Opportunities for Learning: The curriculum minimally addresses daily caregiving routines, which are rich opportunities to support toddlers' development and learning in all domains. Welcome to Frog Street Toddler provides limited guidance on how to establish developmentally appropriate schedules and routines for toddlers, such as "follow the same daily schedule" or "tell little ones what is coming next." Additionally, there are only a few examples in the entire curriculum on how to extend children's learning during caregiving routines (e.g., describe actions when changing a diaper or having lunch with little ones; compare real bananas to a photo).

Play and Exploration: The curriculum provides minimal guidance on research-based practices to support toddlers' play and exploration. Welcome to Frog Street Toddler and "Spruce Up Your Space" tips describe how to create an indoor and outdoor environment for active physical play and exploration (e.g., provide plenty of space for physical movement; set up areas of the room with a variety of activities, textures, and materials). The curriculum mentions the importance of free play for children's development and provides some opportunities for open-ended exploration (e.g., painting; building with boxes; exploring shoes). However, many of the suggested activities are teacher-directed and narrowly focus on completing a task in a particular way. Frog Street Toddler does not describe how or when to allow time for child-initiated play throughout the day or how to provide learning experiences based on children's interests, which research shows contribute to toddlers' development in both Approaches to Learning and Cognition.

Language-Rich Environment and Interactions: The curriculum promotes research-based teaching practices to support toddlers' development in the Language and Communication domain, such as using varied types of talk with toddlers (e.g., modeling complete sentences, introducing new words, engaging toddlers in extended discourse). Frog Street Toddler also provides several learning experiences that encourage caregivers to sing songs, recite rhymes, do finger plays, and read books with toddlers. Research demonstrates that these activities support toddlers' emergent literacy skills. The curriculum introduces children to new and interesting vocabulary words each week, but this vocabulary is not based on children's interests or engagement.

Promoting Emotional, Behavioral, and Cognitive Self-Regulation: Frog Street Toddler consistently promotes research-based practices to support toddlers' emotional, behavioral, and cognitive self-regulation. The curriculum gives guidance on how teachers can use emotional coaching to help toddlers understand and manage their emotions. Similarly, Welcome to Frog Street Toddler provides strategies to facilitate the development of emotional and behavioral self-regulation skills, such as discussing basic rules and offering choices to children. Finally, the curriculum offers many activities to support toddlers in developing executive functioning skills (e.g., Simon Says; Stop and Go; acting out rhymes and songs).

Facilitating Cognitive Development: The curriculum promotes some research-based teaching practices to support toddlers' development in the Cognition domain. For example, the curriculum encourages adults to scaffold toddlers' problem-solving skills by modeling strategies, introducing a process (e.g., identifying a problem, generating possible solutions, trying out solutions), and allowing children to solve their own problems (e.g., understanding why a block tower tumbled down, retrieving a ball out of reach). Many of Frog Street Toddler's activities provide prompts for teachers to extend toddlers' learning, such as providing language-rich input about objects or experiences and asking open-ended questions. However, there is less information on how teachers can intentionally support toddlers' cognitive development during play and open-ended exploration. Similarly, the curriculum features several activities that focus on introducing toddlers to math language and concepts, but the curriculum does not specify how to embed math language and concepts into daily caregiving routines (e.g., mealtimes, diapering, toileting).

Supporting Physical Development: Frog Street Toddler consistently promotes research-based practices to support toddlers in the domain of Perceptual, Motor, and Physical Development. For example, the Activity Guides and Photo Activity Cards provide learning experiences to support toddlers' gross and fine motor skills (e.g., jumping, climbing, using paintbrushes, manipulating play dough). Similarly, the Activity Guides and Photo Activity Cards suggest intentional teaching practices to support perceptual understanding and perceptual-motor development (e.g., asking children to name body parts as they stretch, describing textures as toddlers walk on a tactile path). The curriculum includes many varied opportunities for toddlers to practice new physical skills, such as activities inviting toddlers to put on various clothing items or using physical skills during other self-care routines.

Scope: The curriculum clearly identifies five developmental domains: Language Development, Cognitive Development, Social Emotional Development, Physical Development, and Approaches to Learning. Welcome to Frog Street Toddler provides an overview of each learning domain and "What You Can Do" to support children's development in the learning domains. The Activity Guides provide several examples of learning centers and activities to support children's development in each of these areas.

Sequence: Frog Street Toddler provides a sequence of learning experiences that progressively builds children's knowledge and skills as they move through the developmental progressions in Approaches to Learning and, to some extent, in the domains of Language and Communication and Social and Emotional Development. The curriculum lacks clear sequences of learning experiences that support children's Cognition and Perceptual, Motor, and Physical Development. For example, in the domain of Language and Communication, the curriculum includes three Developmental Storybooks that present a story at three different levels, ranging from simple text to more complex vocabulary and sentence structure, which allow teachers to support children with various levels of receptive language and vocabulary. However, many of the activities that support language development and literacy do not progressively increase in complexity across the Activity Guides (e.g., the language activities in Activity Guide: Theme 2 and Activity Guide: Theme 13 focus on reading the same book with very similar prompts).

In the domains of Cognition and Perceptual, Motor, and Physical Development, the curriculum introduces advanced skills and concepts early in the sequence before building foundational knowledge and skills. For example, an early activity in Activity Guide: Theme 2 invites children to draw their family, count their family members, and match blocks to family members in order to practice one-to-one correspondence. For a young toddler, this is quite an advanced skill. It is built on practicing more foundational skills such as counting and identifying quantity. Yet, the text provides minimal activities that focus on counting or identifying quantity leading up to this activity. Similarly, Activity Guide: Theme 1 invites children to do several complex physical tasks without reference to any prior experiences developing more foundational physical skills (e.g., moving balls on the floor with their chins, putting on their shoes without bending their knees). While Frog Street Toddler provides multiple related opportunities for children to explore or learn concepts and skills in all domains, the sequences of learning experiences in some domains do not fully reflect children's developmental progressions.

Alignment with the ELOF: A thorough review of all curriculum materials indicates Frog Street Toddler is fully aligned with the Head Start Early Learning Outcomes Framework (ELOF) domains and sub-domains. The learning experiences described in the Activity Guides and Photo Activity Cards support children's development and learning of skills and concepts presented across all ELOF sub-domains.

Learning Goals: The curriculum provides the Frog Street Toddler Learning Goals, which are developmentally appropriate, measurable goals organized around the curriculum's five developmental domains. The learning goals are integrated throughout the Activity Guides in the sections, "Starting the Day" and "Approaches toward Learning." Additionally, the learning goals for the weekly developmental activities are provided in the Lesson Planner forms located on the Assessment and Planning CD. Generally, the weekly developmental activities support the learning goals. However, the Lesson Planners list multiple activities under a set of learning goals, and at times it is unclear which or how activities support the goals. The curriculum lacks guidance on how to use the learning goals with diverse children or how to modify learning goals for activities in order to individualize learning experiences for all children.

Ongoing Observation and Documentation: The curriculum describes how ongoing assessment is a process used to understand children's developmental progress, plan individualized activities, and guide instruction. It includes brief descriptions of observation, anecdotal records, and work samples. The Assessment and Planning CD offers specific tools that can be used to support teachers in observation and documentation, such as Anecdotal Observation Record forms. At the end of each week, the Activity Guides prompt teachers to engage in the assessment process, such as by inviting teachers to select one to two children to observe specific skills during activities from the week. Depending on the particular skills observed, the curriculum may suggest teachers record a written anecdotal observation, take a photograph, place a work sample in a portfolio, or add a dated entry to a developmental checklist.

Standardized and Structured Assessment Instruments: Frog Street Toddler describes and provides a structured assessment tool, the Frog Street Toddler Developmental Checklist, that aligns with the curriculum's learning goals. However, the curriculum lacks guidance on how to choose a standardized and structured assessment instrument that is valid, reliable, and individually, culturally, and linguistically appropriate.

Communicating with Families: Welcome to Frog Street Toddler discusses the importance of two-way communication with parents and offers some guidance on how to communicate with families (e.g., the parent bulletin board, parent letters). The Planning and Assessment CD provides materials for communicating with families, including a Toddler Daily Report, All About Me form, and 52 Parent Letters. The Toddler Daily Report and All About Me forms invite parents to share information about their child with the teacher, such as the child's daily routines at home, likes, and dislikes. All forms for communicating with families are translated into Spanish, but no further guidance is provided on how to communicate with families from diverse cultures or who speak home languages other than English and Spanish.

Engaging Families: Welcome to Frog Street Toddler provides some guidance on how to engage families (e.g., invitations to staff training, encouraging use of the school resource library). The 52 Parent Letters provide specific suggestions for how to extend children's development and learning at home (e.g., singing songs in the car; helping children develop self-care skills at home, such as washing hands or serving food during mealtimes). The Activity Guides prompt teachers to share the Parent Letters with parents at the end of each week. The Parent Letters are translated into Spanish, but there is no further guidance on how to engage families who speak languages other than English and Spanish, are from diverse cultures, or whose adult members have disabilities or other special needs.

Professional Development: Frog Street Toddler offers a range of in-person courses, including both initial (Frog Street Toddler Curriculum Implementation) and ongoing (Frog Street Toddler Curriculum Follow-Up) training sessions. Additional courses cover a wide range of content, such as family engagement and how to plan age-appropriate activities in each domain. The curriculum also offers professional learning webinars that can be customized to meet the needs of programs using a pre-webinar questionnaire to identify challenges and share successes.

Curriculum Materials to Support Implementation: The curriculum includes a comprehensive set of materials to support implementation. The online portal houses three introductory videos, which provide an overview of the curriculum materials. Similarly, Welcome to Frog Street Toddler describes the program components and how to use the various curriculum materials. The curriculum features 13 Activity Guides that provide weekly lesson plans. The guides include materials, vocabulary, learning centers, and plans for activities that support children's development in specific domains. They also embed prompts for teachers to implement assessment and family engagement. Frog Street Toddler comes with wall posters to remind teachers of best practices for supporting child development.

• Fidelity Tool: The curriculum offers the Frog Street Toddler Administrator Classroom Observation Tool for Curriculum Fidelity. Program administrators or coaches can use the tool to assess toddler teachers': sensitivity to children's social and emotional needs; instructional strategies implemented individually or in small groups; classroom environment; and intentionality in supporting learning.

Active Exploration: Welcome to Frog Street Toddler discusses how toddlers need space and opportunities to move freely and explore with all of their senses. Some of the suggested learning centers and activities in the Activity Guides allow children to actively explore their environment by providing various objects for filling and dumping or offering several boxes for playing and building. However, many of the activities are more teacher-directed. These invite children to do something very specific, leaving less opportunity for toddlers to engage with the environment in open-ended ways. For example, one activity has toddlers sit in a chair and use their toes to move cotton balls from one bowl to another. In another activity, teachers model how to make a paper chain and children are directed to do the same thing.

Interactions That Extend Children's Learning: Frog Street Toddler provides specific guidance throughout the Activity Guides and Photo Activity Cards on how teachers can engage in interactions that extend children's learning. There are many prompts for teachers to describe objects, narrate what adults and children are doing, ask children questions, and make connections to children's previous experiences. For example, as children manipulate play dough, teachers are encouraged to discuss the dough's texture, color, and smell. Another activity focuses on round objects and invites children to think of other objects that are round. However, some prompts within activities are too advanced for toddlers. For example, an early activity in the curriculum prompts teachers to ask toddlers if they can feel vibrations when talking normally, but not while whispering. Other prompts elicit very specific or limited responses from children which would not extend their exploration, thinking, or communication (e.g., during a painting activity, one prompt asks, "Which yellow color is darker?;" during block play, another prompt reads, "Do the red materials make you think of something red to build?").

Individualization: The curriculum provides some guidance on how to individualize learning experiences for all children. The Activity Guides provide many songs, vocabulary, and prompts in Spanish, but provide no guidance on how and when to use the Spanish translations with children who are dual language learners (DLLs). Welcome to Frog Street Toddler offers a few general tips for working with children with specific needs (e.g., visual challenges, cognitive challenges, speech or language delays). The Activity Guides provide very few adaptations for children with specific needs (e.g., adaptations for two activities in a four-week Activity Guide). Similarly, the curriculum very minimally addresses how teachers can individualize learning experiences for children from diverse cultures, such as inviting them to share about celebrations in their family or offering chants and rhymes from diverse cultures. However, the curriculum lacks comprehensive, in-depth guidance on how to individualize learning experiences for children from diverse cultural backgrounds, children who speak languages other than English and Spanish, or how to modify the majority of activities for children with various types of disabilities, suspected delays, or other special needs.

Environment: The curriculum provides specific guidance on how to design well-organized, engaging indoor and outdoor learning environments. Welcome to Frog Street Toddler provides overarching guidance on how to set up learning centers, and the Activity Guides offer weekly learning centers (e.g., Construction, Discovery, Library and Listening, Sensory Table, Math) to support toddlers' development across all ELOF domains. The Activity Guides also include suggestions to "Spruce Up Your Space," such as setting up areas of the room with a variety of activities, textures, and materials, allowing children to make choices, and providing open and quiet spaces. Welcome to Frog Street Toddler provides some strategies for ensuring the physical environment is accessible to children with specific special needs, but the curriculum lacks guidance on how to include children's home or tribal languages and cultures into the physical environment.

Learning Materials: Welcome to Frog Street Toddler and the learning centers described throughout the Activity Guides offer examples of materials that may support open-ended exploration and inquiry (e.g., blocks, play dough, dramatic play props, stack-and-nest sensory toys). Similarly, the curriculum suggests some manipulatives that could be used for open-ended exploration and inquiry (e.g., balls, beanbags, eyedroppers). Frog Street Toddler provides a few suggested materials for children with specific disabilities (e.g., simple adaptive devices such as pencil grips, clothespins for children with delayed motor development). However, it lacks guidance on how to select learning materials that authentically represent the cultures, ethnicities, and home languages (beyond English and Spanish) of children in the program.

Schedule and Routines: Welcome to Frog Street Toddler provides minimal guidance on how teachers can build a schedule flexibly around children's routines or how to effectively support children's development and learning during caregiving routines. There are some brief suggestions scattered throughout Welcome to Frog Street Toddler, including describing actions while changing a diaper in the "Learning Domains" section; following children's cues rather than a predetermined schedule in the "Nutrition" section; following the same daily schedule in the "Transitions" section. However, they do not offer comprehensive, in-depth guidance for how teachers can establish a daily schedule or fully take advantage of caregiving routines in order to support toddlers' development and learning.

Interactions: Welcome to Frog Street Toddler includes a brief section on "Cultural Sensitivity," with very few tips that could be used to build relationships with children and families from diverse cultural backgrounds (e.g., treating people as individuals rather than stereotypes, focusing on similarities and differences without making judgments, modeling respect for others). The Activity Guides occasionally mention the importance of culturally responsive interactions (e.g., being sensitive to cultures in which children making eye contact with adults is not an acceptable practice, talking with families to build an understanding of how their children's culture differs from the teachers' and attempting to reconcile those differences), but provides no guidance on how to use that information to engage in culturally responsive interactions.

Learning Experiences: The curriculum includes only a couple brief examples of providing learning experiences that build on families' cultures. One activity invites children to share about celebrations in their families, with a note for teachers to be sensitive to cultural differences. In addition, there are a few examples of "Cultural Rhymes" in the Activity Guides that may build on families' traditions and culture if they share that particular cultural background. The curriculum lacks guidance on how to engage toddlers in caregiving routines that build on families' traditions, cultures, values, and beliefs.

Learning Environment: Frog Street Toddler offers two suggestions for providing learning materials that reflect children and families from diverse cultures and ethnicities: present a variety of foods for snack and lunch and use books, photographs, and posters that celebrate a wide variety of ethnic groups. Additionally, the curriculum's Literature Library and Photo Activity Cards include books and photos representing children and families from diverse cultures and ethnicities. However, the curriculum lacks any guidance on how to select and use learning materials that authentically represent the cultures and ethnicities of children and families in the program.

Linguistic Responsiveness: Frog Street Toddler provides minimal guidance on how to intentionally support the development and learning of toddlers who are DLLs. The Activity Guides provide songs, prompts, and vocabulary in Spanish, but the curriculum lacks guidance on how to intentionally use the Spanish translations or integrate other home or tribal languages into the learning environment, experiences, or routines. In addition, some of the Activity Guides include a suggestion related to children who are DLLS, like using concrete materials to help DLLs understand vocabulary and using words from children's home languages if possible.

Teaching Practices and Interventions: Welcome to Frog Street Toddler includes general strategies to support children with visual, hearing, or cognitive challenges, delayed motor development, speech or language delays, and behavioral, social, or emotional challenges. Some of these strategies are research-based teaching practices, such as breaking down a challenging task into shorter segments or providing information in a variety of ways (e.g., verbal cues, gestures). In addition, some Activity Guides offer "Adaptations" to modify activities for children with specific disabilities (e.g., describing colors to children with visual challenges by using things they can smell). However, not all Activity Guides include "Adaptations" specifically for children with disabilities or other special needs, and even those that do include only one or two teaching practices for the entire four-week set of activities.

Learning Environment: Welcome to Frog Street Toddler offers a few strategies to ensure the environment and materials are accessible for children with visual, hearing, or cognitive challenges, delayed motor development, speech or language delays, and behavioral, social, or emotional challenges. Suggested strategies include seating a child in order to optimize vision (e.g., consider lighting and glare), using line drawings with minimal background clutter, providing simple adaptive devices, and changing a child's position. In addition, the Activity Guides give specific examples of how to adapt materials for children with specific disabilities or other special needs (e.g., providing wider-grip paintbrushes).

Individualization Based on Interests: Frog Street Toddler briefly mentions the importance of activities based on children's interests. It states, "Children are more likely to engage in activities that coincide with their interests...Notice what children are interested in and follow their lead." However, the curriculum does not provide any guidance on how to plan learning experiences that build on individual children's interests. Activity choices are pre-planned and there is no guidance on how to modify them based on individual children's interests.

Individualization Based on Strengths and Needs: Frog Street Toddler provides specific guidance throughout the Activity Guides on how to make learning experiences responsive to children's strengths and needs. All throughout the Activity Guides, a blue, upward arrow indicates a modification for older children and children who have already mastered earlier skills and concepts (e.g., one activity invites all children to identify facial features and emotions, and the arrow prompts teachers to ask the children why they might be sad or happy). Similarly, the Activity Guides offer "Adaptations" for several activities that may target younger children or children with disabilities, suspected delays, or other special needs (e.g., providing clues to children as they search for a musical toy).