More than eight in 10 New Jersey high schoolers got their diplomas in 2003, making the state’s high school graduation rate the nation’s highest, according to a new national study. The statewide graduation rate was 84.5 percent in the 2002-2003 school year, according to the study by Editorial Projects in Education, the Maryland-based nonprofit organization that publishes the influential newspaper Education Week. The national graduation rate was just under seven in 10, according to the study. While the high school graduation rates are considered one important measure of school systems, it’s deceptive in this case, according to the study’s authors. That’s because New Jersey provides ways for students who fail required graduation tests to get diplomas anyway. Some students who receive diplomas in New Jersey would not meet the requirements to get them in other states, said study author Christopher B. Swanson. “It doesn’t mean the state isn’t doing some good things to improve the graduation rate,” Swanson said. New Jersey officials are planning to eliminate the alternate path to graduation, which is used by some 20 percent of the state’s graduates and half in the state’s poorest cities. Some education officials have said the alternate method of graduating hurts students by not requiring enough of them. By contrast, some of the states with lower graduation rates offer certificates of attendance or other acknowledgments short of full diplomas to students who do not pass graduation tests. The study found that New Jersey students are most likely to drop out during or just after 10th grade. Across the country, students most often quit school in ninth grade. As with most data on New Jersey’s public schools, the graduation rate study points to some wide disparities. More than eight in 10 white and Asian students graduated, but fewer than seven in 10 black or Hispanic students did. Jay Doolan, an acting assistant state education commissioner, said New Jersey officials are pleased to rank first, but are focused on raising graduation rates, especially among black and Hispanic students. ``We do know we need to work hard to ensure that all of our students are prepared for a career in this global economy,’’ Doolan said. ``Some of our subgroup populations are not where they should be or where we would like them to be.’’