You asked whether the Minneapolis school district’s later high school starting time had any effect on students’ grades or scores on standardized tests.

SUMMARY

Researchers at the University of Minnesota who evaluated the effects of the time change in 2001 found no statistically significant improvement in students’ grades during the three years after the change compared to the three years before it. The researchers did not evaluate students’ performance on standardized tests because Minnesota did not have a comprehensive high school testing program during the three years preceding the schedule change.

This report is based on an executive summary of the 2001 evaluation study’s major findings published online and on telephone conversations with Dr. Kyla L. Wahlstrom, the study’s lead investigator, and Dr. Robert McCauley, Minneapolis’ secondary school superintendent. The Legislative Library is obtaining a copy of the full evaluation and it will be available there soon.

EVALUATIONS OF MINNEAPOLIS HIGH SCHOOL START TIME

In the fall of 1997, the Minneapolis school district moved the start of the school day at its seven high schools from 7: 15 a. m. to 8: 40 a. m. (Dr. McCauley told us on the phone that Minneapolis high schools currently start at 8: 30 a. m. ) The effect of the starting time change has been examined twice, once in 1997-98 and again in 2000-01. Only the 2001 evaluation included an evaluation of the effect of the change on academic performance. (OLR Report 2001-R-0256 has information concerning the initial evaluation results. )

Both the original and follow-up evaluations were carried out by the University of Minnesota’s Center for Applied Research and Educational Improvement (CAREI). The main findings of the follow-up evaluation were published online in August 2001. The complete study, with all supporting statistics, was published in the December 2002 Bulletin of the National Association of Secondary School Principals.

EVALUATION FINDINGS REGARDING ACADEMIC PERFORMANCE

The 2001 evaluation looked at the effect of the time change on student attendance, enrollment, sleep habits, and grades. The researchers found statistically significant improvements in the first three, but not in grades. A “statistically significant” difference means that a change is highly unlikely to be attributable to pure chance.

To determine the effect on grades, evaluators analyzed the letter grades high school students earned in classes during the three years before the change to a later starting time and during the three years after. They found “a slight improvement in grades overall, but the differences were not statistically significant. ”

Grades were the only measure of student academic performance the Minnesota researchers evaluated, according to Dr. Wahlstrom. The evaluation did not address standardized test performance. Minnesota did not have a program of comprehensive testing for all high school students during the three years before the time change (i. e. , from 1993 through 1996). Though the state has such tests now, it is not possible to make valid comparisons between pre- and post-1997 performance.

Researchers decided not to evaluate academic performance using SAT or ACT college admission test scores because the students who take those tests are a self-selected, “nonrandom” group of higher performing students and the data would not be valid for all Minneapolis students, Wahlstrom said.

JL: ts