Facial recognition technology has greatly advanced since 2000, according to a study overseen by the National Institute of Standards and Technology, although it still has some kinks to work out.

The most recently tabulated test, one of several biannual tests conducted by four federal government agencies and involving products from 10 companies, shows that the success rate of face recognition systems in correctly matching faces to images stored in databases has significantly improved.

But the report of the test's findings also included the systems' shortcomings. The test showed recognition systems perform poorly in outdoors settings. Even the best systems made correct matches to the database of images just 50 percent of the time. And the report suggested that other aspects of the systems' search capablities need more research. For instance, they tend to identify men better than women and older subjects better than younger ones.

The government's testing was performed last summer but the results were not fully tabulated and analyzed until recently. The report was strictly a technical evaluation and did not address any privacy or civil rights concerns.

Companies will most likely use the results of the testing to promote their products as effective tools in verifying that people are who they claim to be and in identifying unknown people by comparing them with a database of images. Facial recognition technology is already being used by some government security officers in conjunction with fingerprinting and other biometric systems to perform these tasks.