The Web filters are part of the government's $128 million Plan for Cyber Safety and are undergoing a series of six week trials with eight Internet Service Providers.
Internet Society of Australia president Tony Hill said it is up to parents, not the Web filters, to prevent children from being exposed to graphic material.
His comments follow reports by the that violent sexual acts were falsely edited into a Wikipedia entry on the novel Mrs Frisby And The Rats Of NIMH, which is listed prescribed reading for year 5 to 9 students.
"Filtering is often seen as the total solution, but won't solve all problems. It wouldn't stop children handing over personal information in chat rooms, and offensive content in e-mails," Hill said.
"It is very hard for a manual process to keep up with the creation of pages on the Internet - blacklists tend to not cover the full range of offensive or illegal material.
"It's much better for parents to take a strong interest in what their children are doing. Their degree of supervision needs to correspond with their maturity."
The group discussed the wider implications of Web filtering, beyond its technical ramifications, in a meeting last week in Google's Sydney offices.
has pointed to the trials in response to suggestions the technology is not up to the job, and says the scheme is part of wider plans to combat the proliferation of child porn, including education and law enforcement.
Hill said teachers and parents should investigate material on sites such as Wikipedia before allowing children access.
The false entry was removed within an hour by Wikipedia's internal content filtering technology.