What the Research Says

Five Rules for Reducing Class Size

A report from the American Educational Research Association confirms that smaller classes can produce lasting gains, particularly for minority and low-income students. "Class Size: Counting Students Can Count" synthesizes research on class size and concludes that the greatest impact is seen in the early grades. For maximum effect, class size reduction efforts should meet five conditions:

• Start in kindergarten or first grade; early intervention is key.
• The ideal number of students in a class is 13 to 17.
• If resources are scarce, target at-risk students first.
• To maintain intensity, students should experience small classes all day, every day.
• Small classes should last at least two years, and three to four years for the longest-lasting benefits.

It's Not Just About the Numbers:
Smaller Classes Need Supportive Policies

SERVE examined statewide class size reduction initiatives in Tennessee, Wisconsin and California, as well as efforts in two North Carolina school districts. Reducing class size works best when schools can support efforts with the right funding, accountability, and staffing policies. SERVE offers a number of publications outlining research and recommendations for implementing class size reduction efforts for policy makers, parents, teachers and administrators.

Smaller Class Size Improves Achievement, Voucher Plans Don't

In January 1998, the Keystone Research Center published a comprehensive review of research on two high-profile ideas for raising educational achievement: lowering class size in the early grades and instituting private school vouchers. Alex Molnar’s "Smaller Class Sizes and Educational Vouchers: A Research Update" (1999) emphasizes results since early 1998. There is no cost to download the 50-page study as a PDF here, but free registration is required to gain access to the publication.

Wisconsin Class Size Program Produces Positive Results

Wisconsin's Student Achievement Guarantee in Education (SAGE) program increases the achievement of low-income students in grades K-3, according to a 2003 study by the Education Policy Research Unit at Arizona State University.

The SAGE program, now in nearly 600 schools, reduces the student-teacher ratio to 15:1 in K-3 classrooms. The September 2003 study from Arizona State University concludes that the SAGE program:

• Increases student achievement.
• Upholds gains through 3rd grade.
• Is most beneficial to African-American students.
• Narrows the achievement gap between African-American and white students.
• Compensates for poor attendance.

Smaller Classes Produce Long-term Gains in Student Achievement

Widely regarded as the "gold standard" of class size research, Tennessee’s Student Teacher Achievement Ratio (STAR) Project concluded that smaller classes yield educationally and statistically significant gains in student achievement. Project STAR was a four-year longitudinal study that followed students from kindergarten through grade 3, starting in 1985-86 with kindergarten and ending in 1988-89 with third grade.

The Star Follow-up Studies in 1996-97 ( PDF, 74k, 26 pages) revealed that high school students placed in classes of 13 to 17 children from kindergarten through third grade outperformed students in standard classes of 22 to 25. The students in the initial study now are entering adulthood, and the follow-up study results point to a possible lifetime of benefits from small class sizes.

U.S. Dept. of Education Class Size Report

In its first year, the federal class-size reduction program helped nearly two-thirds of the nation's elementary schools hire an estimated 29,000 new teachers, according to The Class-Size Reduction Program—Boosting Student Achievement in Schools Across the Nation: A First-Year Report , a report released by then-Secretary of Education Richard W. Riley.