Internet filters set at the least restrictive level blocked 1.4 percent of health sites, and blocked some 5 percent of sites when set at their intermediate level. However, when researchers set filters at the most restrictive configuration, 24 percent of non-pornographic health sites were blocked.
The study used results of software from six different companies and concluded that the filtering levels had a greater impact than the type of software used.
Even at the least restrictive level, filters block about one in ten non-pornographic results from searches on the terms “condoms,” “safe sex” and “gay.” At the intermediate level between 20 and 27 percent of results were blocked, depending on the search term.
Paul Resnick, associate professor at the University of Michigan’s School of Information and co-author of the study, said there should be a “public and open process” for deciding how schools and libraries configure filters since “those settings matter.”
The percentage of pornographic sites that filters blocked did not change significantly depending on how the filters were configured. At the least restrictive level, filters blocked an average of 87 percent of all pornographic sites and 91 percent at the most restrictive level.
In a study completed in December 2001, Kaiser found that among the 90 percent of 15 to 24 year-olds who have gone online, 75 percent have used the Internet to find health information, compared to 46 percent who have checked sports scores online. Half of those studied used the Internet to look up information on a specific disease and 44 percent sought information on pregnancy, birth control, or STDs.
Among 15 to 17 year-olds who have sought health information online, nearly half have been blocked from viewing sites they say were non-pornographic.
Dr. Caroline Richardson of the University of Michigan Medical School, the study’s co-author, told the Associated Press that filtering software on public computers in schools and libraries can discourage research on health issues by people who need it most.
“People who are least likely to have access to the Internet at home are also at highest risk for some of the medical problems they might be able to get information about on the Internet,” she said. “The Internet is a way to disseminate accurate and easy-to-access information in a timely manner; if that access if blocked, it’s not clear that everybody will find the information some other way.”
Concerns about young people’s exposure to online pornography sparked the passage of the Children’s Internet Protection Act (CIPA) in December 2000. This act requires schools and libraries receiving federal funds to block inappropriate Internet content through the use of filtering software. The law requires blocking of sites that are obscene, contain child pornography or are “harmful to minors” — a standard set by local communities.
The CIPA requirement for libraries was struck down by a circuit court in spring 2002 on the grounds that it violates the First Amendment, although that decision is currently being appealed to the U.S. Supreme Court. Meanwhile the CIPA requirements for schools have not been challenged and 73 percent of schools already employ Internet filters.
Richardson predicted that some software filters probably would block access to Web pages with details from this research. The study’s results were being published this week in the Journal of the American Medical Association.