WASHINGTON — For families with children, the quality of local schools is often a key factor in deciding which house to buy.

Buyers trying to determine if the schools in a neighborhood will meet their needs can find plenty of data on the Internet about standardized tests, but they shouldn't neglect the value of visits to the schools and old-fashioned word of mouth, say real estate agents and education experts. Don't expect the agent to judge the schools for you.

"When my clients begin to ask questions about the quality of the school system, I try to be careful with labeling schools as 'good' or 'bad' that could be construed as code words to discourage certain groups of people from buying a home in a particular neighborhood, which is a violation of the Fair Housing Act," said real estate agent Thomas Minetree.

Individual schools often have Web sites, but their claims should be taken with a grain of salt, education experts say. "You never see any that says they have a rotten math department," said Georgia Irvin, an educational consultant and former director of admissions at Sidwell Friends, a private school in Washington once attended by Chelsea Clinton, among others.

Besides, whether a school is "good" depends on more than test results, she said. One important factor is "appropriateness for their own child," said Irvin, author of "Georgia Irvin's Guide to Schools: Metropolitan Washington, Independent and Public/Pre-K-12." That includes the availability of nonacademic programs. "Some children need adequate outdoor space for a range of athletic options. Some need a relatively well-developed arts program. Some need very small classes."

You can find some of this information online, but none of this Web surfing is a substitute for visiting the schools, education experts say.

Call to make an appointment to tour the school and meet with the principal, said Karin Chenoweth, author of "It's Being Done: Academic Success in Unexpected Schools." "If the principal says 'no,' right there, that's a problem."

Such visits usually last up to an hour. "You're not going to find out everything you want to know on a tour. You find out enough to know if you want to apply" if it's a private school, Irvin said.

What are you looking for? "Facilities should be safe and hospitable," Irvin said. Ask about security and disciplinary policies, as well as classroom arrangements and teaching styles, she said. Find out if the school has accommodation for children with special needs. Ask about homework expectations.

Other ways to meet staff and parents are to attend a PTA meeting, a back-to-school event or a spring fair, said Chenoweth, a former education columnist for The Washington Post. Attending such events can help you see if it's an "engaged school versus a dispirited school."

Talk to the neighbors, including by approaching people you see gardening, Chenoweth said. "But what you don't want to do is drive up, ask what school someone's kids go to, then sneer when they tell you."

If you know that you want a specific public school, real estate agents can help you find a home within that school's boundaries, by using that as a criterion as they search the multiple-listing service. But don't rely only on information from the sellers or their agent, Minetree said. Double-check the school boundaries with the school board.

Buyers should keep in mind that school districts aren't permanent. As populations shift, schools are built or closed, and boundaries may be redrawn.

Buyers in an area where the population of school-age children is booming or declining can ask school officials how they plan to deal with the long-term effects of those changes.