First Edition Findings

Several quantitative studies have examined the impact of the first edition of Investigations on student learning and achievement.

The book Standards-based School Mathematics Curricula: What Are They? What Do Students Learn? (Senk and Thompson, 2003) provides analysis of research on K-12 Standards-based curricula. In the Investigations-specific chapter, Learning to Reason Numerically, Jan Mokros presents a summary of quantitative studies focused on the number and operations strand. Analyses revealed that:

  1. Investigations students perform as well or better than students using other curricula on computation problems involving basic facts and whole number operations.
  2. Investigations students have a better understanding of number and number relationships than students working with more traditional programs.
  3. Investigations works equally well with students at different levels of achievement in mathematics.
  4. Students using Investigations achieve greater accuracy on word problems and on more complex calculations than students in comparison classrooms.

For a brief overview of Mokros' findings, see:


See the following reports for further details of the studies reviewed:

  • Flowers, J. M. (1998). A study of proportional reasoning as it relates to the development of multiplication concepts. Unpublished doctoral dissertation, University of Michigan, Ann Arbor, MI.
  • Goodrow, A. M. (1998). Children's construction of number sense in traditional, constructivist, and mixed classrooms. Unpublished doctoral dissertation, Tufts University, Medford, MA. (For a summary see Modes of Teaching and Ways of Thinking.)
  • Mokros, J., Berle-Carmen, M., Rubin, A., & Wright, T. (1994). Full-year pilot grades 3 and 4: Investigations in Number, Data, and Space. Cambridge, MA: TERC.

To review a related study conducted during the initial field-testing of the curriculum, see:


Since Mokros’ review there have been several other large-scale student achievement studies.

  • The ARC Center Tri-State Student Achievement Study (ARC Center, 2003) provides evidence of positive impact. This large-scale study of three states, revealed that average scores of students in schools fully implementing Investigations in Number, Data, and Space, Math Trailblazers, or Everyday Math as their core mathematics curriculum were significantly higher than the average scores of students in matched comparison schools not using these curricula.
  • Using data from the original Tri-State Student Achievement study, Gatti (2004) compared the performance of Massachusetts’s students in schools fully implementing Investigations to students in schools from the original matched group in that state (schools not using Investigations, Math Trailblazers, or Everyday Math). Massachusetts was chosen because it had more Investigations users than any of the other states in the original ARC Center Study. The analysis revealed the same pattern of results. Students in schools fully implementing Investigations in Number, Data, and Space outperformed peers from the original set of matched schools.
  • In Assessing Elementary Understanding of Multiplication Concepts (pdf), Smith and Smith (2006) describe a classroom study that compared the most proficient 2/3rds of a third grade Investigations class to the most proficient 2/3rds of a fourth grade class that had been taught multiplication using more traditional methods. The goal was to compare student learning under an instructional approach that emphasizes drill and practice to a more conceptual approach. All students were assessed with a 26-item test that included bare number sentences, conceptual questions, and word problems. The Investigations third graders significantly outperformed the traditionally taught fourth graders on the test as a whole. Moreover, the third graders achieved a higher percent correct within each category, although the difference was statistically significant only on the conceptual questions. The authors argue that the third graders' understanding of multiplication helped them accurately solve more traditional problems, supported their multiplicative reasoning, and resulted in an ability to apply what they knew to word problems.
  • In 2009, Mathematica Policy Research reported the results of the first phase of a study designed to compare mathematics achievement for students assigned to one of four elementary mathematics curricula. In order to participate in the study, school systems agreed to have curricula randomly assigned to classrooms over an extended period of time. Of 118 districts fitting recruitment criteria and contacted by the researchers, 4 agreed to participate. The first phase of the study examined first grade performance. Student achievement was measured by the ECLS-K. Whether the ECLS-K is correlated with state assessments or aligned with the curricula studied is unknown. It was found that first grade students assigned to Investigations 1st edition did not perform as well on the ECLS-K as students assigned to two of the other three curricula. However, there were differences between groups that make this result difficult to interpret. Most of the teachers in the study reported teaching from traditional textbooks over the past five years, and none reported having used Investigations, although some did report past use of other curricula examined in the study. There were also differences between schools in the availability and use of mathematics specialists. Teachers assigned to teach Investigations had the least access to mathematics specialists. The researchers also reported that one of the two higher performing curricula in this study averaged one hour more of mathematics instruction per week than other curricula in the study. Given the inconsistency of the results of this study with other findings, it is unclear whether the differences have to do with methodological aspects of the study, outcome measures, context of implementation, or the grade level assessed. Future phases of this research are expected to use the second edition Investigations materials.