in Box 7-5. In addition, the researchers’ inclusion of multiple curricula also facilitates generalization beyond the effects of a specific curriculum to the broader approaches that may be embedded in it.
The ability of curricular research to inform effective practice would also be enhanced if individual curricula more clearly defined the instructional approaches embedded in them. Often curricula distinguish themselves in terms of content (e.g., covering geometry or not) and generalized approach (e.g., whole-group versus small-group instruction) more than in the instructional strategies that are endorsed and supported in the activities. Thus, any findings that one curriculum is more effective than another provides little knowledge about specific teaching strategies that may be useful.
The limited amount of time devoted to the subject of mathematics may account for why Head Start children make little or no gain in mathematics. For example, using randomized assignment, the Head Start Impact Study found no significant impacts for the early mathematics skills of 3- or 4-year-olds (U.S. Department of Health and Human Services, 2005). Other examples include control groups from experiments (Clements and Sarama, 2007b; Clements and Lewis, 2009; Starkey et al., 2006). The control group in one study, for example, made small gains in number, but little or no gain in geometry (Clements and Sarama, 2007b) and Head Start children made no significant gain in any area of mathematics during the school year (control classrooms continued using their school’s mathematics activities, which were informed by a mixture of influences ranging from commercially published curricula to homegrown materials based on state standards).
Research demonstrates that interventions with a primary focus on mathematics have the potential to increase the mathematics achievement of children living in poverty and those with special needs (Campbell and Silver, 1999; Clements and Lewis, 2009; Fuson, Smith, and Lo Cicero, 1997; Griffin, 2004; Griffin, Case, and Capodilupo, 1995; Ramey and Ramey, 1998), which can be sustained into first (Magnuson et al., 2004) to third grade (Gamel-McCormick and Amsden, 2002). For example, both the Building Blocks and Big Math for Little Kids curricula significantly and substantially increase the mathematical knowledge of children from low-income families (e.g., Clements and Lewis, 2009; Clements and Sarama, 2007b, 2008a). The success, even in comparison to other curricula, is probably due to the shared core of learning trajectories (teaching-learning paths) emphasized in the curriculum and the professional development that ensures that teachers spend time teaching appropriate mathematics topics during the year.
Another example, the Rightstart program5 (Griffin, Case, and Siegler,