When Molly McGowan needed a pediatric urologist for her daughter, she found one in the old-fashioned way: she asked around. Her sister, a nurse, didn't know of anyone in Binghamton, N.Y., their hometown, but a friend who lived next door to a urologist passed along the name of a specialist in Rochester.

It was a three-hour drive each way, but it was worth it. "He was at the top of his field, but he didn't act like it," Ms. McGowan said. "He never seemed rushed, and he explained everything without talking down to us."

Most people wouldn't buy a new car without checking consumer ratings, but they still rely largely on word of mouth to select a physician. Yet with more patients having to choose from a health plan's list, there is growing demand for information that is more reliable than a friend's recommendation and goes beyond the rudimentary details available online: a doctor's hours, educational background and ZIP code.

Unfortunately, it is very hard to get. There are very few good quality measures available to assess individual doctors, so consumers must be prepared to do some research if they want to find a physician they can work with comfortably.

"The truth of the matter is that people are hard pressed to make well-informed decisions when they choose a doctor, and they're doing it blind," said Joyce Dubow, a senior adviser in the office of policy and strategy at AARP. "We don't have objective data, so we use family and friends. And that's not objective."

Businesses, health plans and government agencies have developed rating systems for hospitals in recent years, but they have lagged in developing quality measures for doctors.

"We are really in the early days of physician-specific reporting," said Dr. Carolyn Clancy, director of the Agency for Healthcare Research and Quality. "The challenge is to do it well, so that it's accurate, so that it gives consumers good information about making choices and gives doctors information about how and where to improve."

One problem, she explained, is figuring out how to compensate for different outcomes from different doctors because they treat different patient populations, not because they provide inadequate care.

For now, patients cannot get their hands on a wealth of information about physicians that is compiled by government agencies but off limits to the public. A national practitioner database compiles reports of health care providers who have been fired, for example, but the list is open only to hospitals and selected other groups. The Medicare program recently started a physician quality reporting initiative, but it is in its infancy and the information is not yet public.