Scores on Minnesota’s standardized science tests were up this year, although more than half of public school students who took the exams still performed below grade-level expectations.

Overall, 46 percent of the 181,600 students in three grade levels who were tested met or exceeded scoring benchmarks for their age, up from 40 percent in 2008. Results of the tests — given once each in elementary, middle and high school — were published Tuesday by the state Department of Education.

Agency officials seized on the year-over-year upticks and said the raw numbers aren’t as bad as they appear. They said students and teachers are still adjusting to tests that have been administered for just two years and that have a deliberately high bar.

“We would rather have high standards and a high cut score and a lower proficiency rate,” said Deputy Education Commissioner Chas Anderson. “Setting a lower cut score is not going to achieve college readiness or work readiness for all students.”

Mike Lindstrom, executive director of the nonprofit SciMathMN, said he was pleased that students in each grade made gains over their prior year peers. But he didn’t look past the broader picture.

“These are rigorous tests. But in spite of that we would hope that our scores would be better than a 50 percent ranking,” said Lindstrom, whose group works with education and business leader to emphasize the two subjects.

Rather than a straight pass/fail approach, students are lumped into four proficiency categories: does not meet standards, partially meets standards, meets standards or exceeds standards. Anyone with one of the first two designations is regarded as at least a grade behind in the subject.

In fifth grade, the percentage of students deemed proficient or better in basic science was 45 percent; in eighth grade it was a tad below 43 percent. A test covering life sciences such as biology is given once in high school, and the success rate for those teens approached 50 percent.

In all grades, there was a wide achievement gap between white students and minorities.

Unlike fill-in-the-bubble tests for most subjects, students use computers for the science exams.

A high school test taker might face questions about plant genetics, judging by sample questions. A fifth-grader might encounter images of young and old pintail ducks and be asked to point out similar and differing characteristics. Some questions follow short videos; others require the student to plot points on a bar chart.

While standardized math and reading tests are entrenched in Minnesota schools, this was only the second year for the statewide science exams. The science test doesn’t count toward graduation or determine a school’s rating under the federal No Child Left Behind law.

Even so, state officials and science educators say the tests have drawn needed attention to a key area of the curriculum and driven fresh debate over the class time devoted to the subject.

“You now have a test that now focuses attention to it,” Lindstrom said, “so school districts will scramble to be sure they’re aligned with the standards. They’ll rewrite curriculum. They’ll make those natural changes that help those scores immediately.”

Liesl Chatman, director of professional development at the Science Museum of Minnesota, also welcomes the added scrutiny on science, a discipline she considers an “essential literacy” for the 21st century.

Over the past two years, Chatman has held seminars for more than 450 teachers on how to liven up science education and get through to those students who struggle with it.

“It seems like in Minnesota we’ve broken through a little bit of that reading and math are king and queen and everything else takes a back seat,” Chatman said.

State officials are currently updating Minnesota’s science standards, a process that will stretch into the next academic year. They’ve also begun work on the next generation of the science test, which is due to be in place by spring 2012.