Bigger Schools, More Classes Not Likely to Boost Achievement in Iowa's Schools

Last Updated: March 31, 2006

More Doesn't Mean Better

Report PDF (148 KB)
News Release (80 KB)
CONTACTS: Jerry Johnson (author), (606) 831-2571 Marty Strange, (802) 728-4383.
(Washington, DC) Consolidating high schools and offering more classes will not likely raise student achievement, according to a new study of Iowa schools by a national nonprofit organization. Based on results from the most recent state-mandated achievement tests, the study concludes that Iowa’s small school districts are an “achievement blessing” that should play an important role in the state’s strategy to improve education. It recommends these schools be “intentionally supported” in the state’s school funding system.

The study, More Doesn’t Mean Better: Larger High Schools and More Courses Do Not Boost Student Achievement in Iowa High Schools, was conducted by the Rural School and Community Trust, a national organization dedicated to rural school improvement, using data from the Iowa Department of Education and the U.S. Census Bureau.

Consolidation proponents in the state contend that small high schools in small districts are unable to offer a sufficiently broad curriculum, and that offering more courses would lead to higher achievement levels. Some suggest requiring a minimum enrollment of 200 high school students, while others suggest the minimum should be 400 students.

But creating larger school districts with larger high schools would not likely improve achievement, the study concludes, because smaller districts already perform as well as larger districts and do more to reduce the negative impact of poverty on student achievement.

The study analyzed test scores, curriculum, and demographic data from high schools below and above each of those enrollment numbers and found a consistent trend. Using a 200 student cutoff, smaller districts produce a slightly higher—but not statistically significant—percentage of students who scored “proficient” on state math and reading tests than did larger districts. Yet these smaller districts offered fewer courses and served more impoverished student populations.

Comparisons using the 400 student cutoff produced similar, but stronger results with regard to achievement levels and courses offered.

The study found that student achievement levels are not influenced by the number of high school credits offered. To the extent there is any effect, it is mildly negative—the more credits offered, the lower the test scores—but that relationship is not strong enough to be statistically significant.

The study also compared the relationship between poverty and test scores in larger versus smaller districts, and found that smaller districts cut poverty’s power over achievement by 65% to 81%—depending on the test measure and the enrollment size used to define a “small” district.

Using regression analysis, the study measured how reading and math proficiency varied with other factors across the entire range of school sizes, rather than comparing one group to another. The results were consistent with the earlier findings: larger districts magnify the negative effects of poverty on achievement, while smaller districts reduce poverty’s negative influence.

These results suggest that increasing district size in Iowa would increase poverty’s power over student achievement in Iowa’s schools and widen the achievement gap between wealthier and poorer students.

The study can be read or downloaded online at

Related Categories: Media

Related Tags: RT Policy Department