IF AS MUCH EFFORT were spent getting the content of textbooks into schoolchildren's heads as is spent getting the textbooks into schoolchildren's hands, perhaps the decline in the quality of American education could be reversed.

In spite of the scrutiny -- even hysteria -- that greets textbooks today, this most tangible part of the education process gets but a sliver of the dollars that are spent on education. So, the publishers -- there are some 50 elementary and secondary school textbook publishers, but only about 10 are considered major -- compete intensely for those dollars. And they compete in a system that Robert T. Rasmussen of the Association of American Publishers (AAP) describes as "hedged about by an incredible tangle of laws, administrative regulation and customs unlike those imposed on any other commerical venture."

Total sales of elementary and secondary school textbooks came to about $1 billion last year. The amounts to .75 percent of all educational expenditures. That figure is down from 1.2 percent in 1975. According to Rasmussen the reduction is due less to declining numbers of school children than to the fact that in most school districts money for textbooks is a discretionary item, and is often considered expendable in the face of mandatory increases in salaries, energy and transportation.

A graphic illustration of this was the 1976 decision of the District of Columbia's school board not to buy any textbooks that year as a budget cutting move. As a result of that and the lax inventory system, lack of penalties for students who lose books and an absence of consistent purchasing procedures, many District students this year have had no classroom textbooks -- a situation the District is attempting to correct according to James Taylor, assistant director of the Office of Educational Services.

Another way of dealing with the budget crunch is to impose a textbook fee on students. Currently Fairfax County has finished its perennial ritual of considering such a measure. It has never been approved.

In 1979, the year for which the latest figures are available, Virginia, Maryland and the District spent $23 million, $15 million, and $4 million respectively on textbooks. How they all came to decide which publisher should get their money demonstrates, in miniature, as well as any part of the country the fact that as far as purchasing textbooks is concerned, "The fifty states all do things differently, and so do the school systems within the states," according to an AAP spokeswoman.

Virginia is one of 22 states, mostly in the South and the West called "adoption" states. This means that a state committee reviews all submitted textbooks and decides which should be made available. Virginia's system offers more leeway than some adoption states, in that local school boards can then choose from a number of state approved books, rather than being given books purchased by a central committee for use in all the state's schools.

Virginia has a six-year selection cycle for its textbooks, with a group of subjects coming up for review every two years. The process of approval for an individual text runs about eight months.

Success or failure in getting approval by a large adoption state can make a big difference in a publisher's balance sheet. For example, Texas -- which accounts for 7 percent of all textbook purchases -- put off scheduled textbook acquisitions in 1980 because of political fights. That accounted, in part, for unexpectedly weak sales growth in the industry, according to one financial analyst.

Maryland and the District are 'open' states. That is, each county, or in the case of the District, each school, can decide what materials to purchase for its students. Montgomery County, for example, forms committees of 15 to 25 school district professionals to evaluate textbooks submitted by publishers in each area of study. Since 1976, due to parental pressure, parents have had the right to review material proposed for approval by the county 30 days prior to final adoption. Parents can also request a reevaluation of any approved material, which automatically results in the formation of and ad hoc committee to review the material under question.

In the District, while a teacher textbook selection committee puts together a list of recommended books for city use, school principals have great leeway in deciding which texts will be used in their schools. Salespeople are also allowed to deal directly with individual schools, a practice that is prohibited in Maryland. "If you get on the approved list, that gives you a license to hunt," says one salesman.

Because selling textbooks is, in the words of one salesman, "not like selling in a supermarket, there's no standard way of doing things," publishers spend enormous resources just to get their books noticed. Besides tailoring their sales efforts to meet the requirements of various approval procedures -- and that includes everything from formal presentations befoe state selection committees in Virginia, to door-to-door selling in the District -- publishers must offer samples to potential customers, which often means giving away 10 to 15 percent of the total product in hopes of luring customers to buy the rest.

"Sampling can be like opening up a Pandora's Box," says George W. Cannon, Jr., metropolitan manager for Harper & Row-Lippincott. "Because today's market is so tough, some companies give away all the workbooks that accompany their texts, just so they can get some business. You also have to be careful of requests for samples, when there is no intent to purchase by people who just want to fill up their shelves. You have to monitor that closely."

Another aspect of marketing that has concerned some members of the industry is the expansion in the numbers of those passing judgment on the value of a book. In addition to parents, in some parts of the country, due to pressure from teachers' unions, every teacher in a school system can pass judgment on a text up for approval -- whether or not he or she is familiar with the subject in question.

"For that reason, our marketing challenge is not only to meet [academic] guidelines, but as in the perfume business, make sure the packaging is pretty," says Kathryn Costello, also of Harper & Row. "And packaging adds to the cost of the books."

In addition to the high cost of marketing textbooks, publishers suffer under the same economic conditions that make school boards so tight with the dollar. The cost of paper and postage -- two industry constants -- has skyrocketed in the past few years. Because textbook creation involves so many people -- writers, editors, consultants -- publishers face the same salary pressure that school boards do. It's no wonder, then, that the average price of an elementary textbook went from $3.71 in 1974 to $5.72 in 1979, and high school texts rose from $4.98 to $7.99 in the same period.

The development of a series on a given subject is also an enormously expensive undertaking. "A major revision of an elementary reading text takes 24 to 36 months and costs $12 to $15 million," says David Borrow, a senior vice president at Ginn & Co. "It's a very labor intensive process, and labor costs have gone up."

Because adoption states want to adopt only the most current books, publishers key their up-dates and major revisions to coincide with selection schedules for these states. Industry spokesmen say there is a constant need for revision no matter what the market dictates; history books must be made current, the development of a new teaching process -- such as phonetic approach to reading -- demands new books. But says one publisher executive, "You know what subjects the adoption states want and when. You try to develop your product so that you have material to fill those needs."

With greater attention being given to textbooks as symbols of this country's values, meeting those needs to everyone's satisfaction has become trickier for the industry. Somewhat defensively, one AAP publication says, "Textbooks follow societal changes, they do not lead them. A publisher who tries to force through his books a point of view offensive to society simply finds that the books never reach the classroom." But finding a view that is not offensive to some part of society is a growing industry problem.

Publishing executives point out that they have come very far in meeting the requirements of the left; presentation of more women -- and women in unconventional roles, emphasis on the problems and achievements of minorities, depiction of handicapped children, and discussion of non-nuclear families. But in meeting those needs they often displease the more recently vocal critics of the right, who want to see fewer women bus drivers and more mommies.

"It's one of our most difficult challenges," says Harper & Row's Costello. "We can't be all things to all men. We are under conflicting pressure, so we try to offer a broad representation. For example, women in professions and women at home."

She says that publishers can make some changes to accommodate unhappy selection committees.

"In one of our books we quoted a Carl Sandberg poem which had the words, 'Oh, God.' Some people found this offensive so we got permission from the Sandberg estate to delete it."

But sometimes no accommodation can be reached. When Virginia dropped its elementary school state history text in 1972 because of objections to its portrayal of slaves as happy, it never contracted with a publisher to create a new Virginia history textbook.

Today, the state is using a variety of materials, including, in Fairfax County, a history book written by six Fairfax elementary school teachers, and printed locally.

Then, there are some school board demands that must make many publishers shudder. Take the Family Life and Human Development programs of Montgomery County which request that publishers fulfill their demand: Development of a background to prepare for a deep and meaningful relationship in a permanent and satisfying marriage.

Any publisher who can write that book would be wise to market it outside the classroom as well.