Most Public Schools Managed by Edison Schools Match or Exceed Gains of Comparable Public Schools in 4 to 5 Years

For Release

October 11, 2005

A new RAND Corporation study says most public schools operated for at least four to five years by the for-profit company Edison Schools have shown student achievement gains that match or exceed gains in schools with similar student populations.

The study issued today says that while most Edison schools have shown gains in student achievement in the first three years of operation by the company, their average gains for this period did not exceed those of comparable public schools.

“In most cases, improvement does not happen overnight,” said Brian Gill, a senior RAND researcher and lead author of the RAND Education report. “It takes several years before most Edison schools begin to match or exceed the gains of similar public schools. That's consistent with the findings of other major school reform efforts.”

“The Edison Schools model has potential to improve student achievement at chronically low-performing schools,” Gill added. “Some schools have shown extraordinary gains under Edison's management. But others have not. Each Edison client and community needs to evaluate the success of its own Edison schools individually, rather than looking at average results.”

“Schools face challenges implementing comprehensive reforms, especially in the first year,” said Laura Hamilton, one of the study's authors. “Our study recommends that school districts work closely with Edison before and during the first year of Edison operations, to reduce or quickly address problems associated with the transition or start-up.”

Edison is the largest private educational management company in the United States. The great majority of the more than 140 schools that Edison has run since it began operating schools in 1995 are included in the study, making RAND's analysis the most comprehensive independent assessment of Edison schools ever conducted.

Edison hired RAND in 2000 to conduct a comprehensive and independent evaluation of the performance of its schools. The study is titled “Inspiration, Perspiration, and Time: Operations and Achievement in Edison Schools.”

“Edison Schools commissioned this study as a contribution to the body of work in school improvement – and as an effort to help us serve our schools even better,” said John Chubb, Edison's chief academic officer. “This study will do both, and we salute the RAND team that produced it."

In the 2004-2005 school year Edison served approximately 65,000 students in 103 schools it managed in: California, Colorado, Delaware, the District of Columbia, Florida, Georgia, Iowa, Illinois, Indiana, Massachusetts, Maryland, Michigan, Minnesota, Missouri, Nevada, New York, Ohio, Pennsylvania and Wisconsin. (In addition, Edison also served about 5,000 students in 13 schools in South Carolina to which it provided management consulting services under its “Edison Alliance” program.) Most Edison students come from low-income minority households.

Through 2004-05, 60 percent of the schools operated by Edison have been conventional public schools that were converted to Edison's management, typically by local school districts. The rest of Edison's managed schools are public charter schools that usually started up their operation under Edison management.

The RAND study found that:

  • It is unclear whether Edison's average long-term results exceed or merely match those of comparable public schools. This is because Edison's startup schools by definition lack pre-Edison baseline test results, making it impossible to examine the full period of Edison management using schoolwide scores. RAND examined two alternatives: an analysis of all Edison schools, beginning with scores at the end of the first year of Edison operation, and an analysis of Edison conversion schools beginning from pre-Edison baselines.
  • When Edison schools (both converted and start-up) were examined beginning in the spring of the first year of Edison management, gains of Edison schools and matched comparison schools were similar in years two and three. But by their fourth year of operation, Edison schools' cumulative test-score gains from the first year were larger than those of comparison schools in both reading and mathematics, and Edison schools generally maintained this relative advantage in later years.
  • Converted Edison schools experienced small average declines in achievement during their first year under the Edison system. Achievement in these schools continued to lag behind comparison schools during the first three years under Edison management. However, results improved as converted schools gained experience implementing the Edison design. By year five, the cumulative test-score gains (starting from the year before Edison took over) were similar for Edison schools and comparison schools.
  • Variation among the results attained by individual Edison schools is extensive, with some schools showing gains that far outpaced those of comparison schools, and others falling behind.
  • Edison schools that offered the strongest instructional leaders and the fullest implementation of Edison's curriculum—providing strong offerings in subjects such as science and music along with core instruction in math and reading—showed the largest gains in student proficiency.
  • Edison Schools has an unusually comprehensive set of strategies for promoting school performance. These include an ambitious curriculum, a professional environment that emphasizes teamwork and professional development, and a proprietary online assessment system known as the Edison Benchmarks. This system is used to assess student learning every month and provide immediate feedback to teachers, principals, and Edison central office staff.
  • A high proportion of Edison schools have remained with the company for at least four years, but Edison's contracts have been more stable in charter schools than in district public schools.
  • Edison schools that face fewer constraints on their ability to implement the Edison design seem to demonstrate greater achievement gains than other Edison schools.
  • Edison schools showed gains in both reading and math between 2002 and 2004, confirming results previously reported in Edison's annual reports on student achievement.

Gill said the study's findings that schools with a richer curriculum had higher student achievement has important implications for all educators in light of the increased significance placed on improving test scores under the federal No Child Left Behind Act.

“In order to improve test scores in math and reading to meet the targets in No Child Left Behind, some public schools across the country have narrowed the curriculum, squeezing out fine arts and foreign languages” Gill said. “Our findings should encourage educators who want to maintain a rich curriculum, because they suggest that schools can get students to improve their reading and math skills without giving up other subjects.”

RAND researchers analyzed school-level state test scores from 1995 through 2004 in mathematics and reading at all Edison schools with available data. The analysis includes not only currently operating Edison schools, but also schools that are no longer under Edison's operation.

The achievement results from Edison schools were compared with other schools with similar student characteristics and initial performance levels. RAND research staff also conducted case studies of 23 Edison-managed campuses.

Other authors of the report are RAND researchers J.R. Lockwood, Julie A. Marsh, Ron W. Zimmer, Deanna Hill and Shana Pribesh.

RAND Education conducts research and analysis on a variety of topics, including school reform, educational assessment and accountability, and trends among teachers and teacher training.

A printed copy of “Inspiration, Perspiration, and Time: Operations and Achievement in Edison Schools” (ISBN: 0-8330-3824-9) can be ordered from RAND's Distribution Services ( or call toll-free 877-584-8642).

About RAND

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