As the nation's 83,000 public schools and their 39 million students get back to work for the fall term, ABC has scrapped its usual Tuesday night schedule for a three-hour look at their problems.

Much of what it shows in "To Save Our Schools, to Save Our Children" is vivid and insightful.

There are latchkey children who return from class to empty homes, a teen-age "pop electronic tribal culture" that gives schoolwork short shrift, mediocre teachers' colleges and battles between teachers' unions and state governors over merit pay.

Yet for all the care and time spent -- and after all, three straight hours on the topic seems rather long -- the program passes lightly over the central concern of school policies in recent years: taking steps to raise academic standards after more than a decade of decline.

Instead, the externals of the schools are stressed -- money, race, family structures, and mores -- much as they were by the educational "progressives" who dominated policy-making from the mid-1960s to around 1980.

The show, an ABC "News Closeup" reported by correspondent Marshall Frady, will be seen on Channel 7 starting at 8 p.m. tonight. After a half-hour break for local news, ABC's "Nightline" plans to have more discussion on the same topic at 11:30 p.m.

Some of the most poignant footage of the "Closeup" comes in its first half hour, showing young latchkey children returning in midafternoon to empty homes. The examples used were filmed in Montgomery County, in leafy, middle-class neighborhoods from which most wives as well as husbands now set out to work.

"I get kind of lonely," says 10-year-old Ian Baldwin of Bethesda, who isn't allowed to have friends over when his parents aren't home. He finds it difficult to get down to his homework. "I like to play the radio or watch TV 'cause it sort of keeps me company," Ian explains. Then he adds, "Sometimes it gets kind of boring." Sophie Shive, 8, of Bethesda, often solves the problem of loneliness, her father says, by falling asleep in late afternoon.

Frady contends that with the surge of women into professional jobs, "the higher the educational level of both parents, the higher the odds of them having latchkey children."

He marshals statistics and experts to describe the difficulties latchkey children create for their schools.

There are studies on the other side, of course, which the program doesn't mention, showing that the children of working mothers do just as well or poorly in school as any others.

But the program uses the point to develop one of its main themes, that the "waning of the traditional family" is placing more "custodial" demands on schools while creating students who are "far more difficult" (for schooling) to reach. At the same time, money for schools is "dwindling," it says, and talented teachers are leaving their jobs.

Interestingly, the program lists television, along with drugs, alcohol, part-time jobs and pop music, as a prime creator of the "counter-classroom" culture of many suburban teenagers. Here the example is suburban, middle-class Los Angeles.

Amid footage of teen-agers watching soap operas it cites a study suggesting that heavy TV viewers have lower test scores. One girl describes her day of television -- from cartoons in the morning to "whatever's on at night" -- and declares, "I don't even remember the last book I read."

The show carries at least brief interviews with a galaxy of notable recent commentators on American schools. There are also short segments with U.S. Education Secretary Terrel H. Bell (appearing defensive), Mary Futrell, president of the National Education Association, the country's largest teachers' union (portrayed as feisty) and Albert Shanker, president of the rival American Federation of Teachers (who seems philosophical and conciliatory).

But its most widely used expert -- smiling, soft-spoken and white-haired -- is Ernest L. Boyer, president of the Carnegie Foundation of Teaching and U.S. commissioner of education under President Carter.

Boyer says that teachers should become "more empowered" and expresses fear that the recent increase in "regulations and requirements" imposed by school boards and legislators will make schools "less vital than when the debate (over school standards) began." In general, teachers are portrayed sympathetically in the program, but the NEA doesn't come off so well. It is shown stridently opposing merit pay and competency tests for teachers, particularly in Arkansas, where such programs have been pushed by Democratic Gov. Bill Clinton.

Democratic presidential candidate Walter Mondale is seen at an NEA convention, thanking the organization for its long-time support.

President Reagan also appears with a negative twist, portrayed as a cheerleader for educational quality, unwilling to put federal money where his mouth is.

Indeed, money plays a central role in the program's analysis of what's wrong with the schools.

Yet according to the U.S. Department of Education, average expenditures per pupil rose nationwide by more than a third, even when adjusted for inflation, between 1971 and 1982. They have increased more since then as inflation has abated and a long list of states -- from Texas and California to Florida, Tennessee and Virginia -- have voted large increases in school funds.

The program has lengthy footage on the problems of big-city schools with large, mostly low-income black and Hispanic enrollments. It suggests that their best hope might be to attract more middle-class whites or alternatively to merge with the mostly white suburbs.

But recent test score data show significant gains in such schools, including the District's, particularly in elementary grades and basic skills. Meanwhile achievement has slipped most over the past decade in the affluent suburbs, in high-order skills and among students in the top quarter of the test score distribution.

It is this situation, under the rubric of the "excellence" movement -- with which the current spate of school reform is dealing. How well it is doing this is a serious and important question. Yet this "Closeup" looks the other way.