WASHINGTON – The nation’s fourth-graders and eighth-graders have become better writers, but fewer 12th-grade students can convey well-organized ideas, a new national assessment shows.

Even the signs of improvement must be considered in context: Most students in the three benchmark grades still can’t provide coherent answers with clear language, supporting details, accurate punctuation and creative thinking.

The new report provides a sense of how well students can write essays, communicate information and compose arguments – skills considered essential for success in college and the workplace, yet some educators say writing has become the forgotten fundamental.

The National Assessment of Educational Progress, known as the nation’s report card, charts student achievement and how it changes. It is the latter measure – changes since the last writing test in 1998 – that offers some good news, results released Thursday show.

Maine’s average scores for writing remained stable and higher than the national average for the last four years, according to the report.

The state’s fourth-grade average writing score was higher than those in 26 jurisdictions, the same as in 17 others, and lower than those in Connecticut, Delaware, Massachusetts and New York.

But statewide, only 23 percent of fourth-graders tested at or above a proficient competence level, compared to 27 percent nationwide.

Eighth-graders’ average scores were higher than 30 other states, the same as 11 other jurisdictions, and lower than those in five others.

Statewide, 36 percent of eighth-graders tested at or above proficient levels, compared to 30 percent nationwide.

With only one other year (1998) and one grade (eighth) to compare changes over time at the state level, there was little information to define clear trends in the progress toward the writing proficiency of Maine’s fourth and eighth grade students.

Nationwide, students in fourth and eighth grade showed significant strides in being able to handle challenging writing assignments and applying knowledge to real-life situations.

A range of 28 to 31 percent of students reached at least the mark known as proficient, which is considered the standard for all students. Last time, 23 to 27 percent of students in those two grades achieved at that level.

Also in those two grades, more students reached at least a basic level, which means they could get their point across with at least some effectiveness. The average writing scores increased for whites, blacks and Hispanics in the fourth and eighth grades.

“The nation’s children are writing better, which is indeed encouraging news,” said Education Secretary Rod Paige.

But Paige acknowledged: “We still have to find creative ways to encourage our high school seniors.”

The average test score for seniors dropped slightly since 1998; what’s worse, the proportion of 12th-graders who reached at least the basic level dropped from 78 to 74 percent. That means about a quarter of seniors, within a 25-minute time limit, could not provide an organized answer that showed they understood their task and their audience.

“By the time students graduate high school, they should be able to produce more than disorganized self-expression or Internet chat,” said Marilyn Whirry, former national teacher of the year and a member of the board that oversees the national assessment.

“It is the responsibility of every teacher to lead students in their struggle to become writers.”

The declining performance among seniors has become a trend across topics, as 12th-grade scores have also dropped in reading, math and science in recent years.

In writing, students were given a range of assignments, from writing a letter to a newspaper editor to composing a tale about a character with superhuman ability. The sophistication of the questions grew by grade, as did the expectations of graders, who watched for content, organization, sentence structure, grammar, spelling and punctuation.

In all three grades, about eight in 10 students wrote at a basic level or better. But the performance by the oldest students reflects a deep problem, said Gaston Caperton, president of The College Board, which oversees the college-entrance test known as the SAT.

The SAT will add an essay portion in 2005, and Caperton leads a national commission aimed at improving writing.

“I think the figures substantiate what we’ve said: Young people have got to learn to write,” Caperton said.