When job applicants stroll into the Finish Line, a computer gives them their first interview--and sometimes their last.

The sporting-goods retail chain is among the growing number of companies embracing a new breed of workplace testing aimed at sizing up whether the personalities of job applicants fit with the positions being sought. Depending on how strongly the test-takers agree or disagree with statements like, "You love to listen to people talk about themselves," the computer makes some snap judgments.

At the Finish Line, high scores on qualities such as sociability and initiative earn applicants a "green" seal of approval, enabling them to proceed to interviews with human managers. Scores in the middle rate a "yellow," and a dicier shot at a job. Anyone rated "red" never gets past the screen.

Psychological testing has gained sway at an estimated 40 percent of large U.S. companies, evaluating everyone from hourly employees to top executives, experts say. Businesses such as fast-food giant McDonald's Corp. swear by predictive tests, saying they reduce turnover and boost productivity and sales. Companies spend $400 million annually on employment tests of all kinds.

"I wouldn't hire anybody without one, not any more," said Jack Harms, a Milwaukee-based marketing consultant who uses a 10-minute test to screen corporate sales executives. "In my experience, it's never missed."

Yet critics say the unregulated industry subjects tens of millions to decisions that are little better than coin tosses. Psychologists long have debated whether personality can be reduced to mathematics and whether the power of situations is a bigger factor than personality in determining behavior.

"The best predictor of how someone will behave on the job is usually what they've done before--their record of achievements and not how they answer a test," said Annie Murphy Paul, author of a book that concludes even widely used tests fail to meet basic benchmarks for reliability.

The allure of a simple quantitative system is plain: Bad hires are expensive. On average, businesses spend the equivalent of one year's salary to recruit and train a new employee.

Among the factors driving the testing industry's growth is Internet technology, which makes mass assessments much quicker and less expensive.

Society's tolerance for psychological probing has increased since the Sept. 11 terror attacks, and corporations have grown more rigorous about succession planning and ethics checks.

"People are beginning to realize that screening for thinking style, cultural fit and emotional fit is really important," said Gary Hourihan, president of executive recruiter Korn/Ferry International's 3-year-old assessment business.

Hourihan claims his firm's Web-based tools have been validated in clinical trials that observe employees to see whether their behavior is consistent with their assessments.

"Eighty-five percent will be nailed precisely by the online instrument," he said.

About 2,500 U.S. firms offer tests that purport to identify traits or behaviors that can be related to job requirements. Credible players publish research showing their tests are valid. They also do research to make sure their assessments are valid at the companies where the tests are being used.

The appeal of people-sorting mechanisms is powerful. Witness the popularity of the Myers-Briggs Type Indicator, an assessment system that has been largely discredited as a hiring tool but is widely used in training and development.

The system scores people on how they approach the world using categories such as introversion/extroversion and thinking/feeling and assigns a four-letter acronym that summarizes their personality. An introverted, sensing, thinking, judging person would be an "ISTJ."

Associates at consultant McKinsey & Co. "often know their colleagues' four-letter M.B.T.I. types by heart," Paul writes in her book, "The Cult of Personality: How Personality Tests Are Leading Us to Miseducate Our Children, Mismanage Our Companies, and Misunderstand Ourselves."

"I can't tell you how many business people come up to me because someone has given them Myers-Briggs, telling me, I'm a `this' or `that'" type, said psychologist Leigh Thompson, the J. Jay Gerber distinguished professor at Northwestern University's Kellogg School of Management.

"No academicians worth their salt would put any stock in it," she said.

Some people like labels

Even so, devotees of hundreds of lesser-known assessment systems readily embrace labels, using them as potent frames of reference for hiring decisions.

Marketing consultant Harms uses an online assessment by Kansas City-based Culture Index Inc. to screen corporate sales reps. The 10-minute test consists of two lists of adjectives. Candidates check words that describe them as they are and as they think they would need to be to succeed at work.

"It tells me, here's an ego-driven, empathetic, aggressive, assertive individual--those are the scores you want to have," Harms said. "I'll bring on people with those profiles because at least I know they'll be able to implement" their training.

At the Finish Line, store managers look for "green greens"--candidates with top scores on tests for customer service and dependability.

The Web-based tests were developed by Unicru, a Beaverton, Ore., firm that screens applicants for such chains as Blockbuster. Clients install Unicru's kiosks or computer phones in their stores, where candidates may apply.

Fifteen million people have taken Unicru's customer service test, which consists of statements such as, "You do not fake being polite." Applicants respond on a four-point scale from "strongly agree" to "strongly disagree."

"The kinds of people who do well, they obviously have to have good self-control," said psychologist David Scarborough, one of Unicru's chief scientists. "They have to be patient. They have to enjoy helping people. All those characteristics are quite measurable."

At Finish Line's store in Water Tower Place, manager Michael Frustini screens as many as 70 applicants a week during the store's pre-holiday season.

Frustini is a former social worker who has taken the Myers-Briggs test and swears by his results. "I am that personality," he said, reciting his four-letter type.

Unicru e-mails him the applications of candidates who scored green or yellow. Reds are out of luck.