After seven years on the job, a 30-year-old nurse in a Washington hospital felt "dissatisfied" with the work, though she couldn't put her finger on exactly why.

"I just felt locked in," she says. For a while, she considered giving up medicine "to get into computers."

What changed her mind -- and the course of her career -- was a three-hour battery of tests. The tests, administered by Ability Potentials, Inc. of College Park, helped her, she says, discover her particular work abilities.

"What you need for nursing, I did not have."

For one thing, "You have to pay attention to detail," an ability she did not possess -- at least "not in any great amount." That lack, she found, also ruled out the detail work of computers.

But while she was weak in one area, she scored high on "management" abilities. These results intrigued her.

In the hospital wards, whe says, "I had a thousand ideas, but nobody was interested. As a nurse, you can't carry them out."

She decided, with counseling help from the testing firm, to go back to school for a master's degree in hospital administration. Now, instead of drifting unhappily in her work, "I am very excited. I think I'm going to like administration."

Ability Potentials, a 3-year-old firm established by long-time test experts Joan Bedell and John D. Anderson (formerly with the Johnson O'Connor Research Foundation), is one more in the growing list of new services available to the modern job-holder seeking greater career satisfaction.

People are going to be happier (and the work will be easier), say Bedell and Anderson, if they have the basic abilities for the job.

But, they add, "More people have trouble in their jobs because they have skills or aptitudes not being used." If you're happy organizing things, for example, but your job doesn't call for that talent, you could have a problem.

Attention to detail and an ability to organize are fine skills for an accountant. But they can interfere with the job of the sales manager -- a job calling for someone "active and creative" -- who might spend his or her time "sitting at his desk organizing rather than being out on the road selling."

The accountant whose job doesn't require his talent for developing ideas is -- they suggest in jest -- a potential "embezzler," unless that talent is channeled into some leisure activity.

Bedell and Anderson administer 18 tests in the three-hour session to assess a client's strenghts and weaknesses. Among them:

How quickly you can read and interpret written symbols. "It is used in any clerical task."

The ability to deal with three-dimensional forms. "Basic to the scientific, technical and mechanical fields." If you score low, "Look to the world of words, ideas and people," including law or technology.

How rapidly you produce ideas. "Especially useful in sales, advertising, design and other creative areas."

Ability to "arrange ideas, information or things in a logical, orderly sequence." People who score high here, they say, should consider work "in which there is a recurring need to organize materials or information," such as editing, inventory control, computer programming, travel planning.

Whether you are a generalist or a specialist. Specialists may prefer to work alone in a single field where they can become experts. Generalists "usually prefer working with others" and "require more diversity in their work."

Tonal memory. "The ability to remember sequences of sound. It is basic to the music field, and is particularly useful in learning foreign languages."

Design memory. "This ability to work comfortably with patterns or designs is useful in many fields: art, architecture, engineering, surgery, choreography. If you are high in this aptitude, working in these fields will be easier."

Their tests, Bedell and Anderson point out, measure neiter intelligence nor interests. With the exception of a vocabularly quiz and one or two others, they measure abilities we are born with -- "things you can do almost without thinking." Most people score high on three or four.

Among their clients, they say, are high-school students struggling to decide on a college major, dissatisfied workers in mid-career, and homemakers entering the job market for the first time after their children are grown.

Michael DeSisto, who runs schools for troubled teen-agers in Stockbridge, Mass., and Orlando, Fla., has asked Ability Potentials to test all 300 students and faculty. He calls the testing "marvelous" in helping students understand why they may do better in math than English, or vice versa.

Former Navy chief petty officer Billy Joe Cox of Alexandria, who at 40 felt he was too old "to keep floundering around" in the search for a post-service career, signed up for the tests. He credits them with sparing him the mistake of trying to become " a diesel mechanic," something he thought he might like, but doubted he had the talent for. The tests confirmed his doubts.

Cox is back in college studying business administration, which the tests suggested would be a good outlet for his talents. "I've always enjoyed being around people," he says. "I'm good at administration, and I enjoy a lot of things happening at once."

For Bedell and Anderson, the "art" of their work is interpreting each person's pattern of high, average or low scores. No one flunks -- "Everybody can do something." That can be heartening news to the client gazing dumbfounded at a timed exercise he or she can only leave blank.

In fact, too many high scores can lead to problems. With "too many talents, you can turn out to be a drifter," they say, unless you can find a job that uses most of them

Cost of the test is $125. A written interpretation is mailed out a few days later. Then they make an appointment with the client to go over results. d

Lawyers as a group, say Bedell and Anderson, usually rank high in problem-solving and concept-organization abilities -- "tying together bits of information."

Even with a field such as law, they say, there are choices that could make the work easier and more pleasant.

A lawyer good with three-dimensional forms might turn to patent law. One who scores high on "visual dexterity" -- reading and interpreting written symbols -- should consider tax law. Or if high in idea productivity, courtroom work.

A client may zip through the vocabulary test easily and then be competely befuddled when required to look briefly at a line drawing and then recreate it from memory.

Anyone scoring low on that test of design memory should probably foget, say Bedell and Anderson, about being a surgeon. You're going to have to remember how to put the pieces back where they belong after an operation.