When Lyman Crump graduated with a liberal arts degree he was confident his future rested in an office somewhere. But after working a year as a file clerk, Crump, 31, took a higher-paying job as a janitor.

Clarence Dixon had hoped the five years it took him to earn bachelor's and master's degrees in music would pay off with a teaching job or employment as a professional musician. But when he graduated, the father of four could not find a job in those fields. Dixon, 31, now earns a living writing parking tickets for the D.C. government.

With a degree in chemistry from Hong Kong Baptist College, Johnny Liu, enrolled at Texas Christian University with plans to study medicine eventually. A financial setback threw his plans off track and led Liu, 35, to take a job as a chef.

These people represent a growing trend of the last decade: More and more workers with white-collar credentials are taking blue-collar jobs.

Experts say a variety of factors are involved in the making of these white-collar dropouts:

The white-collar job market is growing, but not as fast as the educated workers trying to enter it. More workers are willing to trade "status" for the blue-collar jobs that pay more or offer greater chances for advancement. Some blue-collar jobs are less stressful and allow for a more leisurely life style. Some workers stumble by chance into jobs they come to love. And the restlessness and job dissatisfaction that burgeoned in the 1960s have continued to grow.

Since 1970, the number of workers 25 to 64 years old with four or more years of college has doubled to 17 million, according to a 1980 survey conducted by the Bureau of Labor Statistics in the U.S. Department of Labor. Another 30 million workers have at least one year or more of college, the same survey reported.

At least one out of five workers in today's job market has completed four or more college years and some experts estimate that as many as half of all college graduates are employed in jobs that do not fully use their educational training.

And while the proportion of college graduates in white-collar work has grown, the number forced into, or choosing to take, jobs outside the white-collar category jumped by 83 percent between 1970 and 1979, according to Russell W. Rumberger, a social researcher at Stanford University and author of the recently published book, "Overeducation in the U.S. Labor Market."

That reflects the enormous impact of the baby-boom population that poured into colleges hoping to exchange a college degree for a high-paying job, according to Denis F. Johnston, a former senior adviser on social indicators with the U.S. Census Bureau. For many, he said, lucrative, satisfying white-collar work has not materialized.

"In another 15 years, the baby-boom population will be out of undergraduate school and college enrollments are expected to take a sharp decline," added Johnston, who is now employed as a senior researcher at the American Institutes for Research. "But with such a large segment of the population today that have attended college, Americans may soon have to accept education not necessarily as a key to better earnings, but as a good in itself."

Robert Quinn, director of University of Michigan surveys in 1969, '73 and '77 that studied the quality of employment and found increasing job dissatisfaction, agrees. "It is automatically assumed that a person who earns a college degree is going to get a white-collar job," Quinn said. "Increasingly, there is little correlation between the type of work a person does and his academic level."

"College graduates historically have been the highest-paid workers in the economy, earning substantially more than persons with high school or community college credentials," Rumberger reported in his book. "But now many other professional and nonprofessional workers command salaries equal to or exceeding those of recent college graduates."

Lyman Crump can vouch for that. He was not sure what kind of job he would get with his degree from the South Central Community College in New Haven, but the odds were good, he thought, that he would find an interesting position that was clean and that paid well.

He landed a job as a file clerk with the Securities and Exchange Commission and worked his way up to GS 4, step 4, earning $12,000 a year before he decided he had a dead-end job.

"The work started to get a little boring," said Crump, the father of two daughters. "I was doing the same thing every day and I knew I could never go higher than a Grade 4 in that job."

After discussing the idea with his wife, Crump decided three months ago to shed his white-collar status and step into a blue-collar job cleaning Metro subway stations for $13,600 a year -- $1,600 more than he earned in coat and tie. Crump said he plans to use his new job as a springboard to better, higher-paying positions in the Metro mass transit system.

But despite the higher pay, Crump acknowledges he faces some quiet frustrations. "Some days," Crump told a recent visitor, "I go to work and I say to myself, 'The work isn't too dirty, the pay is fairly good, and at least I have a chance to move up.' On other days when I have to put my hands into trash soaked with urine or vomit, I say, 'What am I doing here? This job is the bottom. Did I go to college to do this?' "

Clarence Dixon said he was practically through graduate school before he learned the chances were slim he would get a job using his musical skills. "The available jobs in the music field didn't pay a decent salary," he said. "To make good money, you have to have technical training in how to operate electronic equipment in a recording studio or a radio station."

Because he did not have those skills, Dixon, who has an undergraduate degree from Atlanta's Morris Brown College and a master's degree in music from Howard University, went scrambling with his classmates for whatever jobs were available. At first, he worked as a security guard, which paid a "reasonable salary" but had few fringe benefits and required him to work weekends, holidays and unpredictable schedules.

When a job as a "parking control agent," or ticket writer, for the D.C. government came along, he jumped at the $10,800 starting salary, regular working hours, health benefits and other fringes.

"There are a lot of college-educated young people out there who are holding out for a particular job they want," Dixon said. "What they may not realize is that the job market is crowded and if they are serious about earning a living, they might have to alter their career goals a little."

Johnny Liu, who earns more than $22,000 a year as a chef at the Capital Hilton, would have been a physician by now if his plans had worked out. But the scholarship that was to finance his courses at Texas Christian never came through. Out of school and out of money, Liu got married and took a part-time job in the mid-1970s as a cook, a job that turned into a satisfying career.

"I learned to make some Polynesian dishes while I was working part time at the Dallas Hilton," Liu said. "By the time I learned some French and continental dishes, I was committed to a career as a chef."

Liu said his work can be hot, dirty and exhausting. But it has its advantages. "I have two classmates who worked for chemical firms in New Jersey and Minnesota," Liu said. "One was laid off twice, the other has been laid off once. They are constantly worried about their jobs.

"But there is a great deal of job security in working for a restaurant," he added. "My skills are in demand. If this restaurant closes, I know I can go to another restaurant and get a job."

Hoping to boost his family's income, Liu said, he sent his wife to graduate school, where she earned a master's in music voice. But she could not find a job, he said.

Wheeling a 47-passenger motor coach through the streets of the nation's capital was not exactly what Julie A. Alibrando, 28, expected to do after she earned her degree in journalism from the University of Texas. But when she graduated from college, Alibrando found she was likely to earn more in other jobs than she could as a novice in the newspaper business.

At first, she took a job with a mortgage firm that paid a good salary. But she soon discovered, she says, that she would not advance in the banking field unless she returned to college for a master's degree.

But Alibrando did not return to college. She put on a bus driver's uniform, first operating a Metrobus and then, in 1979, becoming a licensed tour guide and bus driver for Atwood's Gold Line tours. Last year, Alibrando said, she earned $20,000 as a bus driver and tour guide. As a beginning news reporter, she would have earned about $12,000.

"I have fantasies of someday going to a small town and working on a small newspaper more as a hobby than a means of livelihood," she said. "By then, I would like to have bought some real estate and built a house. That costs money and I don't mind driving a bus to earn it."

Since Serena Hammond, 25, graduated four years ago from Los Angeles City College with a degree in psychology, she has had a whirlwind tour of the job market as a bank teller, restaurant manager and Metrobus driver. But what she likes best is her present job -- as a janitor.

For Hammond, a single woman willing to stray from traditional work patterns, self-satisfaction has been the key to her employment choices. "I think a lot of people have been persuaded to pursue careers they don't particularly enjoy," Hammond said. "I value being free to choose the type of work I do because it pleases me, not necessarily because of the income. Sometimes I work on a job for a while just to see what that type of work is all about."

Her current employment as a janitor in the Metro system is such an adventure. After working on a variety of jobs, Hammond decided to try her skills with the scrub brush.

"So far, this has been a rewarding and a relaxing experience," Hammond said, as she checked in wearing a brown uniform to begin her work day at Metro Center subway station. "This job has much less tension, no hassle, and not as much responsibility."

Although Johnny Johnson Jr. received a bachelor's degree in elementary education from Howard University last May, he had no intention of being a teacher. He had already decided to be a bus driver because he could earn more money.

In 1980, while he was completing final course work for his diploma, Johnson said, he earned $24,000 as a Metrobus driver. As an elementary school teacher, Johnson estimates, he would earn between

2,000 and

3,000 in his first year.

"I believe my college degree is significant as an intellectual advantage and to make me more culturally aware," said Johnson, who is assigned to a bus route in Northern Virginia. "But when it comes to earning a living, sometimes the best-paying jobs don't require a college education.

"Some people express concern that I'm driving a bus, rather than teaching, which carries more status," Johnson said. "But I try to explain to them that I enjoy a quality life style. And the life style I like costs money."