LINCOLN, Neb. (AP) — One in three Nebraska students who took a new state science exam scored below a level that school administrators consider proficient, according to results released Tuesday.

Nearly 67 percent of the students met or exceeded proficiency levels on the test, which is more rigorous than the science exam given in past years. The test was administered to students in the 5th, 8th and 11th grades.

Nebraska Education Commissioner Roger Breed said the scores represent a new baseline that will help measure student progress in the future. The new scores cannot be compared to older results, he said, because the new science test is more extensive than earlier versions.

"It is what it is, as a baseline," Breed said. "I'll be pleased when it's 100 percent. Until then, I'll consider us as having work to do."

Math and reading scores both improved. More than 74 percent of the students tested in reading met or exceeded state standards, up from nearly 69 percent when the standards were last changed in 2010.

In math, 67.4 percent of the students registered as proficient this year, compared to 62.8 percent in 2011, when new standards were established. Students in grades three through eight and the 11th grade were tested last spring in reading and mathematics.

The results also show more than 73 percent of students tested at or above proficiency levels in writing.

Breed said Nebraska students generally performed at or above the national averages on the tests. The initial results released Tuesday could change slightly when the final numbers come out later this year, Breed said.

"We always would like the progress to be faster," he said. "But we are extremely pleased the progress is trending in the right direction."