Many schools already filter Internet access, especially at the high school and middle school levels, or make distinctions about when filtering is necessary. The 2,700-student Monona Grove district, near Madison,Wis., filters access at its middle school and its high school, but not in its four elementary schools. A kid's never on a computer if there's not a teacher at his right hand. Rise in Filtering A national survey of 400 teachers conducted early this year by Quality Education Data Inc. found that filtering is on the rise nationally with 5 percent more teachers reporting the use of such software this year than they did in 1999. But a provision in Mr. Santorum's bill that would have given local schools the choice of installing filtering or writing a comprehensive policy on dealing with inappropriate content, or taking both steps, was omitted.
Filters also block certain words from appearing on computer screens.
Questions have been raised, however, about the accuracy and effectiveness of filtering systems, which have often been found to block sites that have useful educational information. Peacefire , a Seattle-based advocacy group that opposes filtering, recently tested five filters against randomly selected lists of 1,000 Web sites and reported that between 20 percent and 80 percent of the blocked sites were blocked in error. Officials in the software industry, while dismissing Peacefire's report as unscientific, acknowledge the technology is imperfect. That panel will assist Internet-filtering companies in educating consumers about their products. The ITAA is opposed to a federal mandate on school filtering, Mr. Uncapher said.