Over the past two decades, the United States has spent more than $100 billion on programs to train the poor and "hard-core" unemployed and find them jobs in the U.S. economy.

For most parts, these efforts have taken one of a few specific forms: Make-up for high school dropouts, classes in specific job skills, on-the-job training and government-financed jobs designed to provide "work experience."

And for the most part, they have been a bust.

Now, officials in this former Massachusetts mill town and 14 other cities across the nation are experimenting with a new approach to job programs that could make a major dent in the problem of finding jobs for the hard-to-employ.

The plan, which conbines the resources of a private personnel agency with the counseling and faith-healing techniques of Alcoholics Anonymous, may seem simplistic -- and even a trifle hokey -- to traditional manpower specialists.

But the effort here in Lowell has found jobs for an astonishing 75 to 80 percent of the participants -- all of them former welfare recipients who had been jobless for months.

Neil Hurley, director of the Lowell plan, estimates that the successful job effort will save Lowell an estimated $1.5 million of its annual $16.8 million welfare bill this year. (The new program costs about $500,000.)

And because of the plan's striking success, Lowell suddenly has found a shortage of applicants for its longstanding public service jobs program. "We just can't fill the slots anymore," Hurley gloats.

The difference between the Lowell approach and those that most programs have taken in previous years is a fundamental one:

Traditionally, most federal and state man-power programs have been designed to provide jobless persons with some new training or job skill they didn't have before -- to upgrade their qualifications so they can compete in the job market.

What the Lowell plan does, however, is brush aside all these conventions and concentrate instead on placing the job seeker in a slot with a private firm as quickly as possible. In Lowell, most applicants find jobs within two weeks.

The philosophy behind the Lowell approach is that the major obstacle for most would-be job seekers is not so much their lack of marketable skills as that they just don't know the ropes when it comes to getting and keeping a job.

Lowell's answer is a crash program designed to show the would-be worker how to hunt for job openings, obtain interviews, sell talents to prospective employers and get along on the job once hired.

"I'm learning my way around," said Martha Battle, a 32-year-old welfare mother who has gone for several job interviews in two weeks under the Lowell program. "It's been a real help."

What the Lowell plan does is divide group applicants into "job clubs" of 10 or 12 persons, keeping them together throughout the program -- up to five weeks or until they get jobs.

Each club has a full-time job counselor who works with the applicants, both as a group and individually. The applicants themselves bolster each others' efforts. When one in the group gets a job, everybody cheers.

Job seekers are sent first to stock-taking sessions with counselors to talk about any previous job problems they may have had and how to help resolve them in the future.

The applicants then go through a series of orientation sessions in which counselors go over the realities of the job market -- how to look for work, how much job seekers can expect to earn and what employers expect from workers.

The counselors then help applicants make up presentable job resumes, which the program's clerical staff type and photocopy. Each applicant gets several dozen copies to give prospective employers.

For the next several weeks, the applicants have counselor-supervised job-hunting sessions in the morning and interviews with employers in the afternoon.

Perhaps a major factor in programs's success, all sides agree, is the confidence building and moral support the group approach brings. Program officials say pressure from other applicants makes even the most reluctant club-members overcome their inertia.

And, much like the experience of Alcoholics Anonymous, the program relies on group support to bolster members' confidence. When a job-seeker secures an interview, it's recorded on a wall chart that lists each member's progress.

When applicants get jobs, they write "JOB" in big red letters next to their names -- usually to the cheers and applause of others in the group. The walls of the Lowell job search center are cluttered with these signs of success.

In Lowell's case, the program has a stick as well as a carrot: The job seekers are all welfare clients who have applied for payments under the Aid for Dependent Children program or the Work Incentive Program. Those who don't participate in earnest are denied federal and state welfare benefits.

Under contract from the Labor Department, Lowell is one of 15 sites across the United States where this "job-search" approach is being tested for possible use as part of President Carter's new "welfare reform" program.

The experience is predicated in part on changes Congress made in the federal welfare laws recently to require that applicants for AFDC and WIN program benefits have looked for work first before qualifying for payments.

Although the law has been on the books for years, officials concede it's not really enforced in most cities. Social workers merely list the applicants indefinitely as part of an "unassigned pool," qualifying them without fuss.

In a few cases, welfare clients are referred to the local public service jobs program, where they are assigned to traditional classes, on-the-job training or public jobs under the Comprehensive Employment and Training Act.

What the Lowell System does is demand that welfare applicants to go through the expermental "job-search" program in order to meet requirements that they look for work first. If an applicant refuses, his or her benefits are cut off.

If applicants don't find work through the program within five weeks, they are sent to the CETA program for remedial high school education, vocational training or -- as a last resort -- public service jobs.

But Hurley says the new job search approach has been so successful that a substantial number of the city's traditional CETA training and public service slots are going begging.

"What this program does is to screen out the portion of the welfare population that private employers think can be hired directly -- the people who really are employable, but just don't know how to look," said Hurley.

Hurley also points out that under the Lowell program, it's the firm, not the government, that provides the on-the-job training -- and usually with the prospects that there'll be a slot for the employe to use his or her new skills.

The program has another benefit that Hurely says was unexpected: It helps weed out the estimated 10 percent of all welfare applicants who already have outside jobs and would be receiving benefits fraudulently

Dan O'Connor, a Lowell welfare department liaison officer, says cheaters who already have jobs almost inevitably withdraw their applications rather than spend five full weeks participating in the job-search groups.

"It seems to go a long way to stop that," O'Connor said.

One of the major elements in the program's success also is the fact that it offers child-care services for welfare mothers who take part in the job-hunting effort. The child care is provided by workers trained under the city's CETA program.

Participants also are paid $4.50 each workday during the five-week period to cover lunch and bus fares to their job interviews. Applicants who are late or absent are chewed out and -- occasionally -- docked their pay.

"Going through the program is something like having a job," Hurley said. "It helps instill the attitude that you have to show up every day and do what's expected."

Hurley says the five-week effort costs about $500 a client -- compared with $4,500 a year for welfare payments or $10,000 to $20,000 for a public service job.

But supporters and critics alike caution that the job-search approach isn't a panacea. Alan Fechter, a National Science Foundation manpower expert, warns that the more traditional approaches still are important -- and sorely needed. Experts point to these shortcomings:

Although the Lowell approach seems successful in finding jobs for many hard-to-employ persons, for the most part these are entry-level slots, often at or near the minimum wage.

Supporters point out that getting on the job market bandwagon may well be the most critical step for most hard-core unemployed persons. But critics argue that some applicants could command higher wages with a little training.

Although the Lowell effort has had a spectacular 75 percent job placement rate, the program here is operating under almost ideal economic and social conditions that can't be duplicated everywhere.

A former mill town of 95,000 Lowell is in the middle of an economic mini-boom that has kept the local unemployment rate down to 5.8 percent -- two full percentage points below the national level.

And the city has little of the heavy social and discrimination problems that plague big urban areas. Only 10 percent of the welfare recipients in Lowell are black or Spanish-speaking persons. Three out of four are women.

Program enthusiasts concede the job placement rates in big urban centers are far below the Lowell average, but argue they're still high enough -- 45 to 60 percent -- to make the experiment worthwhile.

Although, Lowell manages to place some 75 percent of the all participants in jobs, critics caution the program should be studied further to see how long the employment-stretch lasts before cutting other programs.

Lowell officials say their own follow-up studies show 85 percent of the job-winners still have their jobs a month after they leave the program and 75 percents remain employed after a 60-day period.

All sides agree that longer-range studies are needed.

Finally, a good many skeptics pooh-pooh the plan as "too simplistic" -- particularly in view of the serious underlying problems so many of the really hard-core unemployed have.

But experts who have visited the Lowell site and seen the results there seem convinced that at the least it represents an approach that is worth exploring further.

And after 20 years of mixed success in attacking the problem, that may not be a bad recommendation after all.