PORTLAND – Maine students performed above the national average but at about the same level as they did five years ago in the National Assessment of Educational Progress.

Nationally, fewer than one in three pupils – about 29 percent – in grades four and eight achieved a skill level deemed proficient or better in 2005.

In Maine, 34 percent of eighth-graders and 36 percent of fourth-graders performed at or above proficient. This was not significantly different from Maine results in 2000.

Also, 72 percent of eighth-graders and 81 percent of fourth-graders were at or above the level of basics in the test. This, too, was largely unchanged.

Maine was not alone in showing no improvement. Most states did not improve in science in grade four or eight. Federal officials did not test large enough samples of students to offer representative state data for grade 12.

Among other findings, Maine students receiving free or reduced-price lunches, about a third of the Maine sample, received scores 11 to 13 points lower than those not receiving free or reduced-price lunches, according to the Maine Department of Education.

The goal of the National Assessment of Educational Progress is for all students to show they can handle challenging subject matter.

Nationwide, 300,000 students were assessed on science. In Maine, 2,700 fourth-graders and 2,600 eighth-graders took the test.