District officials acknowledged that graduation figures are preliminary and need to be verified by the state, but they are sure the higher graduation rates will stick.

"We're confident that it will be either precisely right on or very close because they (state officials) use the same data we use," Superintendent Walt Rulffes said.

The Nevada Department of Education will release the final graduation rate on Aug. 15. The figures released by the school system do not include private school graduation rates.

Rulffes said the numbers reflect an increased focus the district has had in improving graduation rates.

He attributed the improvement to several factors: A million-dollar software program implemented three years ago that allows schools to track students' individual performance and deficiencies; more professional training for teachers along with their willingness to tutor students for the state's proficiency exam; and the two-year emphasis the district has put on having students pass the math portion of the proficiency exam on their first crack as sophomores.

Students must pass the math, reading and writing portions of the state's proficiency exam in order to earn a high school diploma. A student also must earn the 22.5 credits required by the state in order to be considered a graduate.

Rulffes said although the district's graduation rate has increased, he would like to see the improvement continue toward the national average of about 70 percent.

"This is the benefit of good teachers who have focused on critical issues, and it has paid off in terms of increased student performance," Rulffes said.

Sue Daellenbach, academic manager of for the district's Assessment and Accountability Division, said many of the district's efforts have paid off.

"There's been a big push to increase graduation rates and we've made a difference. ... finally," Daellenbach said. "That's a good increase for one year. We hope we can sustain it."

About 548 more seniors received diplomas in the 2005-06 school year compared with the previous year, Daellenbach said.

Rulffes said other programs have also helped increase graduation rates.

The district has expanded the number of schools that offer block scheduling, a model in which a school can offer two more classes per semester than a traditional high school. Block scheduling allows students who are behind in credits the chance to catch up during the year without having to take summer courses.

The school system also has begun a program called Advancement Via Individual Determination, or AVID, which focuses on teens who would be categorized as average students and offers them extra help in math, science and writing. The program's goal is to have such students take advanced placement courses. The program focuses on low-income students and students who do not have immediate family members who have gone to college.

Also, more than half the district's teachers have trained in the past year with the Regional Professional Development Program, an initiative run by the state that offers training for teachers in order for them to keep up with the highly qualified status mandated by the federal No Child Left Behind program.

Bill Hanlon, director of the program, said although the district's graduation rates have improved, the new state-mandated science test, which must be passed by next school year's sophomores and their subsequent classmates, will probably put a dent in the district's improvement.

"The initial results don't look good," Hanlon said of the latest practice test results in science for students in the district. Hanlon said district students on average only answered correctly 37 percent of the questions on the state exam.

"If math caused this problem, science will cause a significant problem as well," Hanlon said.