Kalena Cortes Texas A & M University
Joshua Goodman Harvard University
Takako Nomi St. Louis University
Janice B. Riddell (203) 912-8675, External Relations, Education Next

Increasing Instructional Time for Algebra Boosts Student Performance and Graduation Rates

Taking two periods of Algebra in 9th grade has long-run positive effects on lower-achieving students

CAMBRIDGE, MA – A new study of the Chicago Public Schools’ (CPS) double-dose algebra policy for struggling 9th grade students—the first such study to examine long-term impacts of this intervention—has found substantial improved outcomes for intensive math instruction on college entrance exam scores, high school graduation rates, and college enrollment rates.

“Double-dose” algebra—providing two consecutive periods of math instruction for under-achieving 9th grade students—is considered a potentially promising alternative to the “algebra for all” policy, which encourages more students to take algebra and at earlier ages, but may put struggling students at higher risk of failure.  Today, nearly half of large urban districts in the U.S. report double-dose math instruction as the most common form of support for students with lower skills.

Beginning in 2003, Chicago Schools implemented a double-dose program, and short-term effects were smaller than had been hoped.  Examining longer-term effects, however, the study’s authors found that double-dosed students’ scores on the math portion of the ACT (taken in the spring of 11th grade) were 0.15 standard deviations higher, the equivalent of closing roughly 15% of the black-white achievement gap.  General educational attainment of these students rose:  four-and five-year high-school graduation rates increased by 17 percent and college enrollment rates increased by 30 percent.

“One theory for low high-school completion rates is that failures in early courses, such as algebra, interfere with subsequent course work, placing students on a path that makes graduation quite difficult,” write authors Kalena Cortes, Joshua Goodman, and Takako Nomi in the article, “A Double Dose of Algebra,” which will appear in the Winter 2013 issue of Education Next and is now available online at

The researchers found that the benefits of double-dosing were largest for students whose reading skills were weaker than their math skills.  This finding, they suggest, reflects the additional time spent building verbal and analytical skills; students assigned to double-dose algebra reported more frequently being asked to give written explanations of how they solved a math problem and discussing possible solutions with other students.  Double-dose algebra was found to have “positive effects across the board,” as students earned modestly higher GPAs across all of their non-math courses after 9th grade.

Students also scored nearly 0.20 standard deviations higher on the verbal portion of the ACT, were substantially more likely to pass trigonometry and chemistry classes by 11th grade, and earned higher grade point averages (GPAs) after 9th grade.

Using data that tracked students from 8th grade through college enrollment, the researchers focused on the first two cohorts of students in the program (2003 and 2004), a total of more than 41,000 students.  The primary results are based on comparing the outcomes for students just above and just below the score cutoff for double-dose assignment (11,507 students).

The CPS students in the program were primarily from disadvantaged socioeconomic backgrounds and minority groups; about 90 percent were black or Hispanic.  The findings, note the authors, suggest that the double-dose intervention is “extraordinarily promising when targeted at the appropriate students.”

About the Authors

Kalena Cortes is an assistant professor at the Bush School of Government and Public Service at Texas A & M University.  Joshua Goodman is assistant professor public policy at the Harvard Kennedy School.  Takako Nomi is assistant professor of education at St. Louis University.  The authors are available for interviews.

About Education Next

Education Next is a scholarly journal published by the Hoover Institution that is committed to careful examination of evidence relating to school reform.  Other sponsoring institutions are the Program on Education Policy and Governance at Harvard University, part of the Taubman Center for State and Local Government at Harvard Kennedy School, and the Thomas B. Fordham Foundation.  For more information about Education Next, please visit:

For more information on the Program on Education Policy and Governance contact Antonio Wendland at 617-495-7976,, or visit

Last updated November 1, 2012