How to choose

You'll get no protection if you leave your door unlocked while you're out, as almost 20 percent of those surveyed said they do at least occasionally. Also consider:

Learn lock lingo

The deadbolts we tested are single-cylinder and are operated using a thumbturn. The high-security locks have hardened cylinders, unique pin configurations, and other defenses. Industry rankings, Grades 1 to 3, seemed to track with our Ratings (available to subscribers), with Grade 1 locks being the hardest to disable. But packages don't always display that information, so check company websites.

Decide how much you can spend

A high-security lock of the Medeco caliber might seem expensive, especially if you have it professionally installed. But if you have a break-in, the deductible on your homeowners insurance is likely to be higher than the cost of the lock. And insurance policies commonly give discounts for homes with dead-bolt locks.

Beef up the door frame and lock

Hollow-core or weak doors may give way before the lock does. Whatever type of lock you buy, be sure your strike is made of heavy-duty metal and installed with the 3-inch screws that we think should come with all locks. Hinges should also be secured with 3-inch screws. Some municipalities consider double-sided locks, which require a key on both sides, a fire hazard.

Call the cops

Your local police might have home-security brochures, classes, or even on-site safety inspections. If not, check the National Crime Prevention Council's advice at www.ncpc.org.