Measurement is a critical component of mathematics education, but research on the learning and teaching of measurement is limited. We previously introduced, refined, and validated a developmental progression -- the cognitive core of a learning trajectory -- for length measurement in the early years. A complete learning trajectory includes…

Scaling up educational interventions in the STEM (Science, Technology, Engineering, and Mathematics) field is critical but under-researched. We review and draw implications from a series of studies investigating the long-range impact of an implementation of an early mathematics scale-up model based on learning trajectories. Lasting effectiveness…

Increased attention has been given to learning trajectories (LT) as structural frameworks for educational instruction. The purpose of this study was to explore preschool teachers' descriptions of self-change, seven years after the start of their participation in LT-based professional development and instruction. This study was part of a larger…

Although there is growing interest in implementation fidelity, little research has been reported on the sustainability over time of faithful implementations of learning innovations. This study examined the sustainability of teachers' implementation fidelity to the components of a prekindergarten mathematics intervention two full years after…

Research Findings: We evaluated the fidelity of implementation and the sustainability of effects of a research-based model for scaling up educational interventions. The model was implemented by 64 teachers in 26 schools in 2 distal city districts serving low-resource communities, with schools randomly assigned to condition. Practice or Policy:…

Although some research-based educational practices have shown promise, many fail to be implemented at a scale that affects more than a small proportion of children. Further, research on interventions for young children includes mixed results, with most documenting "fadeout" of effects after several years, but some showing lasting…

We examined whether African American students differentially responded to dimensions of the observed classroom-learning environment compared with non-African American students. Further, we examined whether these dimensions of the classroom mediated treatment effects of a preschool mathematics intervention targeted at students from low-income…

We used a cluster randomized trial to evaluate the effectiveness of a research-based model for scaling up educational interventions, focusing on the persistence of effects with and without a follow-through intervention. The instantiation of the Technology-enhanced, Research-based, Instruction, Assessment, and professional Development (TRIAD) model…

This study used a randomized field trial design to evaluate the efficacy of a research-based model for scaling up an intervention focused on preschool mathematics. Although the successes of research-based educational practices have been documented, equally well known is the paucity of successful efforts to bring these practices to scale. The same…

This study evaluated the efficacy of a preschool mathematics program based on a comprehensive model of developing research-based software and print curricula. Building Blocks, funded by the National Science Foundation, is a curriculum development project focused on creating research-based, technology-enhanced mathematics materials for pre-K…