LITTLE ROCK — Results from national standardized tests show that Arkansas students improved last year in fourth grade science and held steady in eighth grade science, the state Department of Education said Thursday.

The National Center for Education Statistics on Thursday released the 2015 National Assessment of Educational Progress, or NAEP, science scores for those two groups. Arkansas students in both groups scored below the national average.

Fourth graders’ average score in 2015 was 150, up from 146 in 2009, the last year the test was administered, and eighth graders’ average score in 2015 was 148, the same as in 2011, the last year that test was administered.

Nationally, fourth graders’ average score in 2015 was 153, up from 149 in 2009, and eighth graders’ average score was 153 in 2015, up from 151 in 2011.

“These scores provide another tool to help gauge student learning, especially in critical subject areas such as science,” state Education Commissioner Johnny Key said in a news release.

“While they clearly show that improvements are needed, they do not reflect the numerous efforts in the last year to strengthen the K-12 science standards and increase professional development for science teachers,” he said. “We continue to partner with education stakeholders to increase the awareness and importance of STEM (science, technology, engineering and math) education and are committed to ensuring that all students have access to high-quality teachers and student-centered learning opportunities.”

In 2015, 110,800 fourth grade students were randomly tested on NAEP science nationwide, with 2,200 tested in Arkansas, and 107,200 eighth grade students were tested nationwide, with 2,300 randomly tested in Arkansas.

In June 2015, the Arkansas State Board of Education adopted the Arkansas K-12 Science Standards for grades K-eight. Implementation in kindergarten through fourth grade is occurring this school year, with implementation in fifth through eighth grades set for the 2017-18 school year.

The Education Department plans to present grades nine-12 standards to the Education Board in December, with high school implementation planned for August 2018.