New study finds GPAs are better predictors for college graduation than ACT scores

Students’ high school grades are five times better at predicting college graduation rates than their ACT scores — regardless of where they attend school, according to a new study published in Educational Researcher, a peer-reviewed journal of the American Educational Research Association. This conclusion upends the thinking that standardized tests are a more reliable and objective indicator of college preparation because students are evaluated based on the same tasks taken under the same conditions. Every state in the U.S. currently uses standardized tests to assess a student’s college readiness.

Building on existing research that shows high school GPA is a stronger indicator of college completion than test scores, “High School GPAs and ACT Scores as Predictors of College Completion: Examining Assumptions About Consistency Across High Schools” explores questions about the variability of high school GPAs across different schools. Using Chicago Public Schools information, authors Elaine M. Allensworth and Kallie Clark from the Chicago Consortium on School Research compared students with the same GPAs from different high schools — from high-achieving schools to those with low average test scores — and found that the predictive nature of GPAs is consistent across high schools. The researchers asked the same question about ACT scores and found that the relationship between the score and college graduation varied across high schools.

The authors suggest that the wide variety of teachers and content taught in high school contributes to the reliability of GPA as an indicator of academic readiness for college, where students will likely experience even more variation. On the other hand, the study notes that standardized tests measure only a small skill set and that “students can prepare for these tests in narrow ways that may not translate into better preparation to succeed in college.” In fact, the authors found that ACT scores sometimes show weak and even negative relationships when the scores are used to make decisions about students’ ability to succeed in rigorous academic programs.

“It was surprising not only to see that there was no relationship between ACT scores and college graduation at some high schools, but also to see that at many high schools the relationship was negative among students with the highest test scores,” Allensworth said in a statement.

The study found that each incremental gain in a student’s GPA is associated with an increase in their odds of graduating college. The chance of graduating from college ranges from 20 percent for students with high school GPAs under 1.5 to about 80 percent for those with GPAs of 3.75 or higher, after controlling for student backgrounds and college characteristics.

“The bottom line is that high school grades are powerful tools for gauging students’ readiness for college, regardless of which high school a student attends, while ACT scores are not,” said Allensworth.

While standardized tests remain ubiquitous with the higher education application process, a growing number of institutions nationwide — largely small, liberal arts colleges — are test-optional or de-emphasize ACT and SAT scores for admissions.

Two lawsuits filed in December 2019 allege the 10-campus University of California system is violating state civil rights laws by requiring applicants to take the SAT or ACT, which the suits claim discriminate against disabled, low-income, multilingual and underrepresented minority students. The lawsuits were filed on behalf of the Compton Unified School District, four students and six community organizations.