This study takes a look at the achievement effects fo four elementary school math curriculum The four curriculum are Investigations in Number, Data, and Space: Math Expressions: Saxon Math: and Scott Foresman-Addison Wesley Mathematics. Here links to the reports the study has generated.

Achievement Effects of Four Early Elementary School Math Curricula
Findings for First and Second Graders
NCEE 2011-4001
Institute of Education Sciences
National Center for Education Evaluation and Regional Assistance
October 2010

Achievement Effects of Four Early Elementary School Math Curricula
Findings from First Graders in 39 Schools
NCEE 2009-4052
Institute of Education Sciences
National Center for Education Evaluation and Regional Assistance
February 2009