Existing research suggests high school GPAs are a strong indicator of college readiness. But schools, districts, and states overwhelmingly rely on standardized assessments as measures of college readiness for program and policy decisions, due to perceptions that they are strongly predictive of college outcomes, and more consistent measures across schools than GPAs. This study examines variation across high schools in the validity of GPAs as measures of high school achievement and college readiness, relative to ACT scores, using more rigorous methods than in prior studies which have often relied on self-reported grades, and inadequate consideration of spurious factors and school effects. We find considerable variation by high school in college graduation rates for students with either the same GPAs or the same ACT scores—there are school effects which are not captured in either measure of achievement. However, high school GPAs show a very strong relationship with college graduation despite sizable school effects, and the relationship does not differ across high schools. In contrast, the relationship between ACT scores and college graduation is weak-to-nothing once school effects are controlled, and varies depending on the high school a student attends. As researchers and policymakers evaluate practices designed to improve college readiness, these findings suggest that strong reliance on standardized test scores could lead to inaccurate assessments of how well high schools are preparing students for college, and that practitioners and families should rely mostly on students’ GPAs when evaluating students’ college readiness.
This is a working paper. Working papers are preliminary versions that are shared in a timely manner, with the aim of contributing to ongoing conversations in research and practice. They have not undergone the Consortium’s full internal review process, nor have they received external peer review. Views expressed in this paper do not necessarily reflect those of the UChicago Consortium or the University of Chicago. Any errors are the authors’ own.