Katherine Barrett's interest in writing began at age 7 when she wrote a poem. Now, at age 15, she writes lyrics and jots down her thoughts in a notebook.

Over the years, several teachers have praised her writing ability, and Barrett usually gets As or Bs on her English compositions.

But last year she failed the state's functional writing test.

"It doesn't make sense," said Barrett, a 10th grader at Walt Whitman High School in Bethesda who wants to be an actress and musician. "I didn't think I would fail. I didn't think it would be possible."

Writing is also one of Barbara Jones' academic strengths. Jones, an 11th grader at Magruder High School in Rockville, has been an honors English student since ninth grade and has written poetry and short stories since the fifth grade. She failed the writing test, not once but twice. "It doesn't make me feel great," she said.

That Jones and Barrett, good students with proven abilities to write, should fail Maryland's new, state-of-the-art writing test is a mystery to their teachers, and the high percentage of failures is creating controversy around the state.

"I don't understand how it is that kids who are so, so good do not pass [the writing test] and kids who are barely passing English pass the test," said Patricia David, a skills lab aide at Magruder High School in Rockville, who is coaching students who have failed the writing exam.

In some school systems, such as Montgomery County, between 8 percent and 10 percent of ninth grade students in honors English courses have failed the writing test.

Statewide, about 13,700, or one quarter of this year's 11th graders, have failed the test, a graduation requirement beginning in 1987.

Only 54 percent of the ninth graders who took the test last year passed, compared with 51 percent in 1984.

The high number of failures has so alarmed teachers, principals and parents that state School Superintendent David Hornbeck is asking a panel of experts to examine the test for possible flaws. He also has agreed to give this year's 11th graders three more chances instead of the scheduled two to take the test before they are to graduate in June 1987.

Should the panel decide that there is nothing wrong with the test but "thousands of students" are still not passing by 1987, Hornbeck said, he will consider various options, including waiting several years before requiring passage of the test for graduation.

"It would be intolerable, under those circumstances, to victimize the students for the failure of the instruction," he said.

Concern about the fairness of the test has reached the state legislature. Del. Michael J. Collins (D-Baltimore County) said he will file a bill that would suspend the writing test as a graduation requirement until 1989.

Collins, a history teacher, said the state needs more time to "take a look at the test, how it's graded, what it means and who is grading it" before it is enforced as a graduation requirement.

"It's clear that the state does not have the test right," he said.

The writing test has come under increasing fire from many people who question whether it really measures functional writing.

While there appears to be general agreement among parents and teachers that students should be tested for writing skills before they graduate, many wonder if the writing test is the best way to accomplish that goal.

"I think they are asking for professional writing," said Katherine Barrett's mother, Mary Ellen Barrett, a writing professor at American University for 15 years.

Mary Ellen Barrett has reviewed her daughter's writing test essays and says she believes that her daughter should have passed.

She concedes that the essays could have been faulted for poor organization. "It's not great. It's immature. But it is functional writing," Mary Ellen Barrett said.

A score sheet that was returned to Katherine Barrett said her essays were weak in content and conventions, a category that includes grammar, spelling and punctuation. She failed by half a point, with a combined score of 5 out of a possible 8.

Ann Chafin, chief of the program assessment branch of the state Department of Education, called the paper "a close call." She added that Barrett's first topic was too brief and included too few details and that Barrett did not elaborate enough on the second topic.

Why a paper such as Barrett's did not pass has led many parents and teachers to question the way in which the tests are scored, a method that they said leaves too much room for human error. The grading has been done by two out-of-state firms.

On the test, students are asked to write two essays, one narrative and one explanatory. The essays are graded for content, organization, audience, sentence formation and conventions.

Graders use a set of standards developed by the state, but they also rely on their general impression of the paper in assigning a score.

"There is a terrible subjectivity in the grading," complained Anne Atanosian, an English resource teacher at Magruder High School.

Another factor that some people believe may lead to errors in the scoring is the short time a grader spends on a paper. The typical grader reads between 200 and 300 papers a day, spending between 60 and 70 seconds on each paper, said Robert Rentz, president and owner of R&R Evaluations Inc., the Atlanta company that graded Maryland writing tests last year.

"I think that's mind-boggling," said Mary Elizabeth Ellis, a member of the state Board of Education.

Graders, who must have a bachelor's degree in education, English or a related subject, often are recruited through newspaper advertisements. Two graders must read each part of the test and assign a score of 1 to 4.

The scores on the two parts are added, and the sum is the student's final score. Eight is the maximum score; 5.5 is passing.

When the graders disagree on a score by 2 points, a third grader is called in to decide the final score. But if the graders disagree by 1 point -- for example one gives the essay a 2 and another a 3 -- the score is averaged and the final score is a 2.5.

Rentz said many people misunderstand the way writing is tested. "People think the papers are given to teachers who use personal subjective standards to determine what the score is, and that's not what happens," he said. "We use rigorously defined criteria, and the training is also quite rigorous."

English teachers have complained that essay questions sometimes have been confusing to students.

Three years ago, when the test was first given on a trial basis, students were directed to write a letter to someone about a school fair.

"The kids at Walt Whitman don't go to Gaithersburg to attend the county fair," said Bonita Connoley, the English resource teacher there. "They didn't understand what a school fair was . . . . The only fair we've ever had was an art fair. There was no way for them to answer the question. We also had several students from South America, and they said, 'What's a fair?' I said, 'Oh, a fiesta,' and they just looked at me."

The controversy over the reliability of the writing test has led many parents and teachers to ask whether the test is worth the expense.

It costs about $3.50 to grade a paper. By the end of this school year, Maryland will have spent about $1 million in grading the tests since the program began in 1983.

"I'm not sure what we are getting out of the process is worth the money," said Connoley.

Richard Lloyd-Jones, president of the National Council of Teachers of English and a writing professor at the University of Iowa who has written several books on writing, said writing tests are a good diagnostic tool but can backfire when used as a graduation requirement.

"The tests can be helpful but also dangerous when misused," he said. "They can lead one to make judgments about humans that are so far from the mark as to be very unjust, and I think it leads a student to make a judgment about himself that can become a self-fulfilling prophecy."

While state educators concede that there are many valid questions about the test that deserve scrutiny, they are not willing to give up on the idea of making students pass a writing test to get high school diplomas.

Twenty-two states give students writing assessment tests, but only Maryland, Nevada and New York make the writing test a graduation requirement, according to a 1984 report by the Education Commission of the States, an education clearinghouse.

Within five years South Carolina and New Jersey will require a writing test for graduation. Several states, including Georgia, are in the process of developing a statewide writing test.

Maryland is the only state that requires a student to pass four basic skills tests, in writing, reading, mathematics and citizenship, for a high school diploma, state officials said.

Some educators defend the writing test. State Superintendent Hornbeck said he believes that students should know how to write in order to graduate.

"There are people who think I have a special interest in the test, and that's not so," he said. "I do have an enormous interest in kids being able to write and think. That's the objective."

"I think we are asking children to do something that . . . is reasonable," said Dan Nuzzi, a specialist in language arts for the Cecil County school system, where 75 percent of the county's ninth graders passed the test last year, the highest percentage in the state. "Functional does not have to mean the lowest possible level."

At least for the moment, the future of Maryland's high school students hinges on passing the writing test.

Perhaps most frustrating for many students repeating the test is not knowing what they did wrong the first time.

"I don't know what those people are looking for," Barrett said. "I'll go in and take the test and do what I can, and if that's not right I don't know what I'll do."