This nonexperimental, quantitative, cross-sectional, explanatory study (Johnson 2001, p. 10) investigated the differences between a reform-based elementary school mathematics program, traditional elementary school mathematics programs, and General Education student achievement in high-socioeconomic districts on the New Jersey Assessment of Skills and Knowledge (NJASK) at grades 3, 4, and 5. An analysis using correlational statistics of student scores from the 2007 and 2008 administration of NJASK3, NJASK4, and NJASK5, with a sample population of more than 200 New Jersey DFG-I and J public schools with over 60,000 third, fourth, and fifth grade students indicate mixed results for the existence of differences in mean scale scores between schools implementing a traditional mathematics program or a reform-based elementary mathematics program and student achievement on NJASK.

The study found statistically significant differences in mean school scale scores between fourth grade General Education students using the Everyday Mathematics program and those using a traditional program on the 2007 and 2008 tests. Statistically significant differences were also found between mean school scale scores for fifth grade students using the reform-based program and those using traditional programs on the 2008 NJASK5 test. All statistically significant differences favored the Everyday Mathematics schools. Differences on the 2007 and 2008 NJASK3, as well as the 2007 NJASK5 were not found to be significant.

Effect sizes, calculated using Cohen's d, ranged from −0.55 to +2.13 for the Everyday Mathematics program.

Implications: The study results provide information to assist school leaders in selecting elementary mathematics programs. Recommendations for future research and practice are included.