| Abstract: | Abstract This article examines the effectiveness of four elementary school math curricula: (a) Investigations in Number, Data, and Space; (b) Math Expressions; (c) Saxon Math; and (d) Scott Foresman–Addison Wesley Mathematics (SFAW). These curricula are distinct from one another and represent many of the diverse approaches used to teach elementary school math in the United States. The results are based on 39 schools that were randomly assigned to use the various curricula at the first-grade level. The results show that average spring first-grade math achievement of Math Expressions and Saxon students was 0.30 SD higher than Investigations students and 0.24 SD higher than SFAW students. These effect sizes mean that an average-performing student's percentile rank in math would be 9 to 12 points higher if the school used Math Expressions or Saxon, instead of Investigations or SFAW. We also conducted correlational analyses that examine whether curriculum-group differences in math instructional time and content coverage account for the differences in curriculum effects and found that a portion of the relative effects is due to differences in content coverage. |
