Chapel Hill-Carrboro City Schools are investigating why some groups of students perform better than others on their first attempts on end-of-grade tests.
A high percentage of both black and Hispanic students are forced to retake the tests after not demonstrating grade-level proficiency, according to the district's annual proficiency report.
Students in grades five through eight are required to take the state-provided exams.
The district's report states that the greatest number of students retaking the test were black. Hispanic students also retook tests at a higher rate than white students.
Diane Villwock, district testing director, said administrators are pleased with the fact that the percentage of black students who pass the retest is close to the average of all students who pass it.
"It appears the academic effort is working, because students are passing the next week," Villwock said.
But they are not satisfied with the high number of minority students who require retesting.
"The goal during the year is to get everyone proficient on the first test," said Kim Hoke, spokeswoman for city schools.
Villwock could not specify why more minority students failed to demonstrate proficiency on the first test than other groups but said this achievement gap is shrinking.