Students’ high school grade-point averages are five times stronger than their ACT scores at predicting college graduation, according to a study published Tuesday in Educational Researcher, a peer-reviewed journal of the American Educational Research Association. The authors of the study, Elaine Allensworth and Kallie Clark, both of the University of Chicago, also found that the predictive power of GPAs is consistent across high schools. The relationship between ACT scores and college graduation depends on which high school a student attends; at many high schools there is no connection between students’ ACT scores and eventual college graduation. “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,” said Allensworth, who is the director of the University of Chicago Consortium on School Research.