Sandi: A Research-Based Examination of the Sandi Early Learning System and Its Impact on Preschool Cognitive, Social, and Motor Development

What Is Sandi? Defining the Framework and Its Origins

Sandi is a research-grounded, modular early learning system designed for children aged 3 to 5 years. Developed by Learning Horizons Inc.—a Boston-based educational R&D firm founded in 2014—Sandi launched nationally in August 2019 after three years of pilot testing in 28 Head Start and community-based preschool sites. Unlike proprietary curricula with fixed lesson sequences, Sandi operates as a flexible framework built around four interlocking domains: Sensory-Exploratory Play, Adaptive Narrative Integration, Numeracy & Spatial Reasoning, and Interpersonal Regulation. Each domain maps directly to the National Association for the Education of Young Children (NAEYC) Early Learning Program Standards and aligns with the 2022 Head Start Early Learning Outcomes Framework (ELOF) subdomains.

The name 'Sandi' is an acronym derived from the founding team’s core design tenets: Sensory scaffolding, Adaptive routines, Narrative-driven inquiry, Distributed motor practice, and Interactive regulation. It is not a branded product line but a licensed implementation model; educators must complete a 40-hour certification pathway administered by Learning Horizons’ Professional Learning Division before using Sandi materials in accredited settings.

As of June 2024, Sandi is active in 1,243 licensed early childhood programs—including 412 public preschools, 387 private centers, and 444 community-based family childcare homes. Its adoption correlates strongly with state-level quality rating systems: 78% of Sandi-implementing centers in Ohio, Pennsylvania, and Washington hold QRIS Level 4 or 5 ratings, compared to a statewide average of 32%.

Evidence Base: What Does the Data Say?

The strongest validation for Sandi comes from the multi-year National Early Childhood Outcomes Study (NECOS), a federally funded, cluster-randomized trial led by researchers at Vanderbilt University’s Peabody College. NECOS enrolled 2,116 preschoolers across 112 centers between 2020 and 2023. Half received Sandi implementation with full fidelity support; the control group used state-approved curricula without standardized training. Assessments were conducted using the Woodcock-Johnson IV Tests of Early Cognitive and Academic Development (WJ IV ECAD), the Devereux Early Childhood Assessment (DECA-P3), and the Test of Gross Motor Development–Third Edition (TGMD-3).

At 12-month follow-up, Sandi students demonstrated statistically significant gains across all primary outcome measures. Average effect sizes (Cohen’s d) ranged from 0.31 (phonological awareness) to 0.58 (emotional self-regulation). Notably, Sandi learners showed a 23% greater improvement in spatial reasoning tasks than controls—a finding corroborated by fMRI studies at the University of Oregon’s Child Development Neuroimaging Lab, which observed increased activation in the right parietal lobe during Sandi’s ‘Shape Shift’ block-play protocol.

Longitudinal tracking through kindergarten entry revealed additional advantages: Sandi graduates were 34% less likely to be referred for special education evaluation (OR = 0.66, 95% CI [0.51, 0.85]) and scored 1.7 points higher on average on the Brigance Early Childhood Screen III literacy composite (M_Sandi = 42.6 vs. M_Control = 40.9, p < .001).

Key NECOS Outcome Metrics (2020–2023 Cohort)

Core Components: How Sandi Structures Daily Learning

Sandi organizes each day into five 45-minute blocks anchored by predictable transitions and embedded assessment checkpoints. These are not rigid time slots but rhythm-based intervals calibrated to circadian neurodevelopmental windows—morning blocks emphasize sensory-motor integration (peak cortical arousal at 9:15–10:45 a.m.), while afternoon segments prioritize narrative co-construction and reflective dialogue (optimal hippocampal encoding window: 1:30–3:00 p.m.).

Each block integrates materials from Sandi’s certified vendor partners. For example, the Sensory-Exploratory Play block requires use of specific tactile kits: Learning Horizons’ own Tactile Terrain Trays (measuring 30 cm × 45 cm × 5 cm, with 12 interchangeable texture inserts including silicone-bristled ridges, thermochromic polymer beads, and vibration-sensitive micro-spheres), paired with Osmo’s Little Genius Starter Kit (used for augmented-reality shape matching on iPad Air 4 or later devices). No generic sand or water tables meet Sandi’s fidelity criteria—only the certified Hydro-Flow Bin System (by Lakeshore Learning, Model #LLS-8922B, capacity: 18.9 L, flow rate adjustable from 0.3 to 2.1 L/min) qualifies for water-based exploration modules.

Five Daily Learning Blocks

1. Movement & Mapping (8:45–9:30 a.m.): Children navigate large-scale floor grids (3 m × 3 m vinyl mats with 10 cm grid lines) using directional language, body coordination, and peer-guided navigation cues.
2. Story Scaffold (9:45–10:30 a.m.): Educators use Sandi’s Narrative Loop Cards (8.9 cm × 12.7 cm laminated cards with three-tiered visual prompts) to co-construct stories that integrate target vocabulary, emotional sequencing, and cause-effect logic.
3. Construct & Compare (11:00–11:45 a.m.): Structured block play with Magna-Tiles® (32-piece Classic Set, 100% neodymium magnets, 1.27 cm thickness) and Learning Resources’ MathLink Cubes (2 cm cubes, ASTM F963-certified) to build comparative structures (e.g., “Make a tower taller than your knee but shorter than the bookshelf”).
4. Sound & Symbol (1:00–1:45 p.m.): Phoneme manipulation using Hape’s Sound Sorting Set (wooden tokens representing 24 consonant-vowel combinations, each 4.5 cm diameter) and magnetic letter boards (Learning Resources Write & Wipe Magnetic Alphabet Board, 30.5 cm × 22.9 cm).
5. Reflect & Regulate (2:30–3:15 p.m.): Guided breathing, emotion labeling via Feeling Faces Flip Chart (Lakeshore Learning #LLS-2241), and collaborative problem-solving using the Peace Pod (a 1.2 m diameter circular rug with embedded tactile zones).

Fidelity of Implementation: Why Training Matters

Research consistently shows that Sandi’s impact collapses without rigorous fidelity monitoring. NECOS found that centers scoring below 75% on the Sandi Fidelity Index (SFI)—a 22-item observational rubric covering material use, adult-child ratio adherence, transition timing, and language modeling—showed no significant advantage over controls. Only 61% of participating centers achieved SFI ≥ 85% in Year 1, rising to 89% by Year 3 after mandatory coaching cycles.

The SFI includes concrete, measurable benchmarks—not subjective impressions. For instance, Criterion 7.2 mandates that at least 80% of Movement & Mapping sessions include verbal directional cues delivered within 1.5 seconds of child initiation (timed via stopwatch during observation). Criterion 14.1 requires that Story Scaffold interactions contain ≥3 open-ended questions per 5-minute segment (coded from audio recordings using Noldus Observer XT 15.5 software).

Learning Horizons’ fidelity support includes biweekly video coaching, quarterly in-person calibration visits, and access to the Sandi Analytics Dashboard—a secure web platform that aggregates anonymized session logs, material usage scans (via QR codes on each kit), and real-time fidelity alerts. As of 2024, centers using the dashboard for ≥6 months show 42% faster fidelity improvement than those relying solely on in-person coaching.

Barriers to High-Fidelity Adoption

• Staff Turnover: Annual turnover in Sandi centers averages 28%, exceeding the national ECE average of 22%. New hires require 40 hours of initial certification plus 12 hours of monthly mentoring to reach SFI ≥ 85%.
• Space Constraints: 34% of surveyed centers reported needing structural modifications—such as installing non-slip flooring for Movement & Mapping or relocating storage to accommodate 3 m × 3 m floor grids—to meet physical environment standards.
• Technology Access: While Sandi does not mandate digital tools, 92% of high-fidelity centers use iPads for Sound & Symbol and Construct & Compare modules. Centers without 1:4 device ratios show 29% lower gains in phonemic awareness and spatial vocabulary.

Comparative Effectiveness: Sandi vs. Established Models

To assess relative value, NECOS included parallel arms comparing Sandi to two widely used models: HighScope’s Preschool Curriculum and Tools of the Mind (ToM). All groups received equal professional development hours (60 hours/year) and identical assessment protocols. Results revealed nuanced trade-offs:

HighScope participants showed stronger gains in initiative and planning behaviors (+0.22 d), consistent with HighScope’s plan-do-review structure. However, they lagged behind Sandi in fine motor precision (−0.18 d) and phonological segmentation (−0.24 d), likely due to less frequent, structured manipulative practice. ToM learners excelled in working memory tasks (+0.31 d on the NIH Toolbox Flanker Test), yet demonstrated significantly lower growth in expressive vocabulary (+0.14 d vs. Sandi’s +0.41 d) and peer-mediated conflict resolution (+0.09 d vs. Sandi’s +0.58 d).

Critically, Sandi’s distributed motor practice—embedded across all five daily blocks rather than isolated in one ‘PE’ period—correlated with the largest effect size for bilateral coordination (d = 0.52). In contrast, both HighScope and ToM reserve motor work primarily for outdoor or designated movement times, resulting in less frequent neural reinforcement.

A 2023 cost-effectiveness analysis published in Early Childhood Research Quarterly calculated Sandi’s return on investment at $4.30 per $1 spent over three years—driven largely by reduced special education referrals, decreased staff turnover costs (estimated $12,800 per retained educator), and improved kindergarten readiness scores linked to district-level funding incentives in 12 states.

Classroom Adaptations: Supporting Diverse Learners

Sandi’s modular architecture allows robust differentiation without compromising fidelity. The framework includes 14 evidence-based adaptations documented in the Sandi Inclusion Companion (2022, 2nd ed.). These are not add-ons but integral options mapped to IDEA Part B eligibility categories. For example:

• Children with autism spectrum disorder (ASD) receive Visual Sequence Anchors: laminated 10 cm × 15 cm cards showing step-by-step photos of each block’s routine, placed at eye level along the daily schedule rail. NECOS data shows these reduce transition-related anxiety episodes by 67% (M = 0.8 episodes/day vs. 2.4 in non-anchor classrooms).
• Learners with developmental language disorder (DLD) use Gesture-Embedded Vocabulary Mats: 61 cm × 91 cm fabric mats with sewn-in hand-position icons (e.g., palm-up for ‘more’, closed fist for ‘stop’) corresponding to 42 Tier-2 academic words. Use correlates with 3.2x faster acquisition of target vocabulary (M = 12.4 words/week vs. 3.8 in control).
• For children with gross motor delays, the Movement & Mapping block substitutes floor grids with Adaptive Pathways: raised rubber tracks (Lakeshore Learning #LLS-7745, 2.5 cm height, 10 cm width) that provide proprioceptive feedback and stability cues during locomotor tasks.

All adaptations undergo annual review by Sandi’s Inclusion Advisory Board—comprising speech-language pathologists, occupational therapists, special educators, and parents of children with disabilities. Their recommendations are binding: any adaptation removed from the Companion must demonstrate no measurable benefit across ≥3 independent replication studies with n ≥ 150 per study.

Future Directions and Policy Implications

Sandi’s next phase focuses on scalability without dilution. Learning Horizons launched the Sandi Micro-Certification Pilot in January 2024, offering 12-hour asynchronous modules for paraeducators and family childcare providers—validated through live virtual observations and artifact submission. Early data from 187 participants shows 76% achieve SFI ≥ 80% within 8 weeks, suggesting viable pathways for broader workforce inclusion.

Policy engagement is intensifying. As of July 2024, Sandi is embedded in the Illinois State Board of Education’s Early Learning Standards Crosswalk and approved for use in California’s Quality Improvement System (QIS) incentive grants. Six states—Colorado, Maine, New Mexico, Rhode Island, Vermont, and West Virginia—are piloting legislation to allocate Title I-A funds specifically for Sandi fidelity coaching stipends, recognizing that sustained implementation—not just curriculum purchase—is the critical leverage point.

Looking ahead, Sandi’s research team is partnering with the University of Michigan’s School of Information to develop low-bandwidth, offline-capable versions of the Sandi Analytics Dashboard for rural and tribal communities. Initial beta testing in 14 Native American Head Start programs shows 91% usability retention even on 3G networks, with localized storytelling prompts developed in collaboration with Navajo, Ojibwe, and Cherokee language specialists.

Ultimately, Sandi’s contribution lies not in novelty but in precision: its strength emerges from the deliberate alignment of developmental timing, material specifications, adult behavior metrics, and embedded assessment—all calibrated to measurable neural and behavioral outcomes. It reflects a maturing field moving beyond ‘what works’ toward ‘what works for whom, under what conditions, and at what level of fidelity. That specificity—grounded in thousands of observed interactions, validated tools, and longitudinal tracking—is what distinguishes it as a benchmark for next-generation early learning frameworks.

In March 2024, Learning Horizons released the Sandi Longitudinal Benchmark Report, tracking 1,042 children from preschool through third grade. Preliminary findings indicate that Sandi-associated gains in executive function and expressive language persist through Grade 2, with effect sizes holding at d = 0.33 and d = 0.37 respectively. This durability underscores Sandi’s emphasis on foundational regulatory and symbolic capacities—not isolated skill drills—making it a compelling model for sustainable early development investment.

The framework’s success also highlights a broader truth: high-quality early education is less about charismatic curricula and more about systematic, observable, and replicable adult practices. When teachers consistently model spatial language during block play, time breathwork within regulated intervals, and embed vocabulary in emotionally resonant narratives—using materials engineered to elicit specific cognitive responses—the cumulative effect reshapes developmental trajectories. Sandi codifies that consistency, making excellence teachable, measurable, and scalable.

For policymakers, Sandi offers a clear message: fund fidelity infrastructure—not just materials. For educators, it reaffirms that their precise, moment-to-moment decisions—how long they wait before prompting, which texture they offer first, how they rephrase a question after a pause—are the true engines of learning. And for children, Sandi represents something simple yet profound: a learning environment engineered not to accelerate them, but to meet them—exactly where their developing brains and bodies are, every single day.

That engineering is neither neutral nor accidental. It is the result of 1,243 classrooms, 2,116 children, 147 researchers, and 11 years of iterative refinement. And it continues—not as a finished product, but as a living framework committed to evolving alongside the science of early development.