THE QUALITY OF writing in the nation's high schools and colleges -- leaving aside, for the moment, the real world -- is a subject that offers plenty of fuel for pessimism.

Scholastic Aptitude Test verbal scores have been plummeting for nearly two decades, and since 1970 the drop (from a 460 to a 424 national average) has gone way beyond what might be explained by changes in the size or makeup of the population taking the test. Beyond the numbers, the "dumbing-down" of textbooks, the eager abandonment of the old-fashioned "essay exam" and the trauma of job applicants when asked to commit their qualifications to prose, all testify to a state of affairs that should sadden anyone who imagines a connection between writing and the full utilization of the human intellect.

So it is a strange and wondrous, and conceivably even a significant thing, that many of the people closest to the problem -- the teachers of writing, and their teachers -- are sounding more upbeat these days. They think they are onto something, and they want the rest of the world to know about it.

"It's a real simple program and it's had smashing success," says James Gray, supervisor of teacher education at the University of California at Berkeley. "The whole notion that writing is teachable is no longer in question."

"It's a radically different way of approaching education," says Donald Gallehr, associate professor of English at George Mason University. "It's common sense, but it was never done this way before. We work with teachers who have been part of a repressive and suppressive system for years, and we see them break out of that on a regular basis. We've had teachers who were just about ready to quit, then returned to teaching with a fervor . . ."

Gray and Gallehr are talking about the work of the National Writing Project, which arose in Berkeley, Calif., and has since spread to 43 of the 50 states with the help of $2.7 million from the National Endowment for the Humanities. The strategy of the National Writing Project is to make students approach writing differently by making teachers approach it differently. Through summer and year-round workshops for teachers in all grades and disciplines, the project aims to create a cadre of reborn writing enthusiasts who, inside their own schools, will become evangelists for the new faith and be fruitful and multiply.

But the National Writing Project is only the biggest and most visible expression of a surprising consensus that has formed in the last few years around these untraditional notions: that students should get beyond the model of "academic writing" with mere correctness as its goal; that they should write in all classes, not just English; and that instead of trying to produce an acceptable paper all at once, they should be encouraged to keep journals, write drafts, criticize each other's preliminary work and experience the ardor of revision.

Born in the rush toward universal higher education of the late 1960s, the new approach has many birthplaces, but a common parentage: panic. In New York City, for example, an ambitious open enrollment plan created an influx of college students who would never have gone beyond high school otherwise. So after years of hand-me-down status among English teachers, writing instruction suddenly and unavoidably became a high-priority concern. But most of the teachers drafted for the emergency were completely unprepared for it. They were simply "stunned" by the papers their students turned in, as the late Minna Shaughnessy, one of the leaders of the City University's Basic Writing program, wrote in a book about its lessons, called "Errors and Expectations."

"Students write the way they do, not because they are slow or non-verbal, indifferent to or incapable of academic excellence, but because they are beginners and must, like all beginners, learn by making mistakes," Shaughnessy concluded. "These they make aplenty and for such a variety of reasons that the inexperienced teacher is almost certain to see nothing but a chaos of error when he first encounters their papers. Yet a closer look will reveal very little that is random or 'illogical' in what they have written. And the keys to their development as writers often lie hidden in the very features of their writing that English teachers have been trained to brush aside with a marginal code letter or a scribbled injunction to 'Proofread!' "

One CUNY student had written: "I feel that my extending their education it will provide with knowledge, so when they have got to make a decision they can think carefully and consider more than one viewpoint." Looked at from the "error" perspective, such a sentence might seem totally anarchic, Shaughnessy wrote, but on further consideration, most of its problems could be traced, at least indirectly, to a single bad choice--the use of the word "my" instead of "by." Such difficulties with prepositions and connecting words are common among beginning writers, she noted, and when they are explained, dramatic progress often results.

"Some students make such impressive strides within a semester that one can only conclude that competence lay, at the outset, barely below the surface of their performance," Shaughnessy wrote.

Her book was "an absolutely extraordinary book among writing teachers," says Michael Marcuse, assistant professor of English at Maryland University. "It absolutely transformed the way in which I thought about what I was doing."

The Bay Area Writing Project, which Berkeley's James Gray founded in 1974, pioneered the idea of teachers teaching other teachers in an "egalitarian" rather than "top-down" relationship, spanning the grades from kindergarten through university. Gray's concept has since been transplanted, under the National Writing Project umbrella, to more than 90 sites, and the 25 teachers trained in the project's first year had grown to 41,000 as of 1981.

"The momentum of this thing is growing at a rapid pace," says Gray. "In California it would be hard to find a control group that hasn't already been touched by the National Writing Project."

Although the Washington area is not as far along as California, the new approach to writing has gained a firm foothold here too. In February, the Virginia legislature voted a one-year, $210,000 allocation for the state's seven National Writing Project sites, or $30,000 for each. Plans are afoot to establish National Writing Project sites in Maryland and the District as well.

George Mason University, besides serving as home base for the Northern Virginia Writing Project, has adopted a program called Writing Across the Curriculum, whose aim is to prod non-English teachers to require much more writing from their students on a routine basis. Like the National Writing Project, Writing Across the Curriculum has had nationwide support from the NEH, but it is up against a powerful trend in the opposite direction, a trend spurred by rising enrollments and the allure of the computer as a teaching and testing tool. Programmed instruction ("If you get this answer right, then you can move on to the next question") is seen as a particular menace. "The main appeal of it is like the videogames," says Christopher J. Thaiss, who runs George Mason's Writing Across the Curriculum program. "It's got lots of flashy lights. We see that as defeating the ends of education, and it certainly defeats our aims."

Howard University has adopted the same idea with a mandate calling on all its non-English teachers, as of next fall, to incorporate journals, drafts of papers and "free writing" into their instruction. "This is not primarily the function of the department of English," says Estelle W. Taylor, who chairs that department at Howard University, "but a problem that all of us must face together. Many of the deans and many of the chairmen are delighted to have someone say this, to put a stress on actual writing."

Another change at Howard is the creation of an upper-class writing requirement as a follow-up to the existing freshman composition class. Howard has established two new courses -- one for students who get a D in the freshman course, another for students who pass that course with a grade higher than D. (Students who fail the freshman course have to take it again before proceeding to the higher-level courses.)

The University of Maryland, meanwhile, has instituted a junior-year writing requirement that emphasizes nonacademic writing. "This is a course in pre-professional writing that is really geared toward what the students will do once they enter a career," says Shirley Kenney, provost for arts and humanities at Maryland. "It is not Bonehead English." Michael Marcuse, coordinator of the junior composition program, says it reflects "a recognition that preparing kids to write essays for scholarly journals has been abandoned."

Cooperation between colleges and secondary schools is one of the key elements of the new approach, and one noteworthy local example is the Georgetown University-D.C. Schools Articulation Program. Founded by Georgetown's James Slevin in 1978, this program recently received a three-year NEH grant of $200,000, with Georgetown underwriting most of the balance of the overall $250,000 price tag. A multidisciplinary team of Georgetown faculty members works throughout the year with teachers from public and private secondary schools -- specifically, in the 1981-82 academic year, Ballou, Cardozo, Wilson, Mackin and Sidwell Friends. The participating teachers meet every two weeks at Georgetown, and in the alternate weeks there are meetings within each of the schools to address its particular problems.

"The four of us talk about the program a lot and tell each other what we've tried and experimented with," says Patricia O'Connor, chairman of the English department at Mackin High School. "We usually go out to dinner after class and hash it out."

O'Connor is one of four participating Mackin teachers -- two in English, one in history and one in religion. Students in O'Connor's junior English classes are doing more writing this year -- and more rewriting -- than ever before, she says, "and I do give the credit to Jim Slevin's program. They all write journals now. I'm writing a journal too, and they can read mine and I read theirs."

In the past, the time involved in correcting and grading papers was a major disincentive, O'Connor says. "But the beauty of Dr. Slevin's program is he has the kids themselves do a lot of the correcting. That way they see the struggle that comes with writing, and they see that it doesn't all come easy . . . The sharing has been, I think, very good, and they're better, sometimes, at being kind to their peers than the teacher is."

Besides being less of a drain on the teacher's time, the shared approach alters the nature of the rewriting process, and alters it for the better, in O'Connor's judgment. "Writing has been too private for too long," she says. "We try to keep it a secret, those of us who can write, how we do it. When you grade the paper and hand it back and they have to change all the things you circled, that's not rewriting. That's punishment."

As for her students and their writing, "I see an improvement recently," she says. "Kids have heard the word that they can't write, and they want to do better. I promise them that they'll be doing better when they leave me. They hold me to it, too."

Efforts to quantify the success of the writing-instruction renaissance have yet to yield any widely accepted evidence. There have been statistical studies galore, but "most of them turned out to be flawed terribly at the evaluation end," says Michael Scriven of the University of San Francisco, who supervised a three-year independent study of the Bay Area Writing Project. On the other hand, says Scriven, subjective evidence should not be discounted. "Anonymous estimates of the worth of the program by the teachers who went through it were extremely favorable. They felt it had changed them a lot. There's no doubt that they get really revitalized by it. We're losing good, enlightened teachers. This saves a lot of them."