Studies show that the mathematics test-score gap is evident at every level of schooling and can be linked to students' earlier performance. For example, a mathematics performance gap was found in children as young as three years of age (Case & Griffin, 1990; Jordan, Huttenlocher, & Levine, 1992). Addressing the mathematics performance gap early on, before children start school, has therefore become a priority for preschool programs serving children from low-income backgrounds (Clements, 2004). The authors created a research-based model to meet this challenge in the area of mathematics, with the intent that the model generalize to other subject matter areas and other age groups. The specific goal of their implementation of the TRIAD (Technology-enhanced, Research-based, Instruction, Assessment, and professional Development) model was to increase math achievement in young children, especially those at risk, by means of a high-quality field-centered implementation of the Building Blocks math curriculum, with all aspects of the curriculum--mathematical content, pedagogy, teacher's guide, technology, and assessments--based on a common core of learning trajectories. The primary research question of interest is as follows: Do children who are exposed to the Building Blocks mathematics curriculum in preschool perform better on measures of mathematics skills through the end of first grade than do children who were not exposed to that curriculum? This scale-up intervention took place in preschool classrooms in three urban school districts: the Buffalo Public School system in Buffalo, New York, the Boston Public School system in Boston, Massachusetts, and a combination of the Metropolitan Nashville Public School system and the Metropolitan Action Council Head Start system in Nashville, Tennessee. Research has suggested that early curricular effects may fade over time, resulting in very little, if any, discernable difference in elementary school between students who had been exposed to a given curriculum prior to formal schooling and students who were not exposed to such a program, as those without early curriculum exposure "catch up" to their peers (Barnett et al., 1995). In the Preschool Curriculum Evaluation Research (PCER) project, across all 14 curricula, kindergarten effects were nonexistent, prompting a decision not to collect any further longitudinal data. Similarly, with the scale-up project, the authors saw evidence of curricular effects across outcomes at the end of prekindergarten, but very few differences at the end of kindergarten, and virtually none at the end of first grade. Longitudinal research, including follow through interventions in these grades, is needed to determine if these early gains truly "fade," or if, as the authors posit, the problem is that primary grade curricula and teachers do not build upon them.