SOFTWARE FILTERS: HOW WELL DO THEY WORK?

Last week's ruling puts responsibility for determining what children may see on the Internet squarely in the hands of parents and teachers. Several software products, including SurfWatch, Cyber Patrol and Net Nanny, allow adults to screen content on their home PCs, while most of the large online providers offer built-in "parental controls" or free screening software. But computer programs don't obviate the need for adult supervision. Even SurfWatch, which pays graduate students to troll the Internet in search of offensive material, promises only 90% effectiveness. And to achieve that, its software filters must, of necessity, err on the side of caution....