Investigations in Number, Data, and Space® was designed to embody the vision of the rigorous national standards developed by The National Council of Teachers of Mathematics (NCTM), and to invite all K-5 students into mathematics. An extensive body of research on how students learn mathematics informed the development of the curriculum. Researchers in several content areas collaborated directly with the development of the curriculum. These included: Douglas Clements and Michael Battista (geometry); Susan Jo Russell, Jan Mokros, Cliff Konold, and Andee Rubin (data); Ricardo Nemirovsky, Cornelia Tierney, and Tracy Noble (mathematics of change). In addition, the developers drew on the large body of educational research carried out over the past 20 years on students' understanding of number and operations. Current research and reports such as Adding It Up and How People Learn support and expand on these earlier findings.
In Schools and Faimilies: Creating a Math Partnership (2002), Murray summarizes the consensus about the need for new approaches for teaching and learning mathematics:
"In the past few decades, data from a variety of sources have shown that mathematics education in the United States is not serving our students well. [nces.ed.gov/timss/] The data point out that U.S. students need to study more than arithmetic; they need mathematical experience and expertise in areas like geometry, data, and algebra. . . .
In the face of developing knowledge about how children learn and about the weaknesses of U.S. students in mathematics, the National Council of Teachers of Mathematics (NCTM) took action, publishing three documents that laid the foundation for improving mathematics education in the United States: The Curriculum and Evaluation Standards for School Mathematics (1989), The Professional Standards for Teaching Mathematics (1991), and The Assessment Standards for School Mathematics (1995). These standards were designed to help teachers, curriculum developers, and assessment experts create a different vision of mathematics teaching and learning." (p. 43)
Murray also shares that Investigations was developed and extensively field-tested from 1990 to 1998 by a team of curriuclum developers and researchers at TERC. During the field test, the development team spent thousands of hours in classrooms, observing teachers and students as they tried out activities, talking to teachers and students, and collecting student work. Developers found that Investigations works well with a range of students and enables students to delve deepley into mathematical ideas. (p. 43)
The National Science Foundation (NSF) partially funded the development of Investigations in Numaber, Data, and Space® as well as a number of other mathematical curricula. The Investigations curriculum was developed at TERC, a non-profit company working to improve mathematics and science education. Originally published by Dale Seymour, Investigations is now a Pearson product.

