The trial, conducted in Tasmania by the Australian Communications and Media Authority, surrounded guidelines put forth in June 2007 by Helen Coonan, the previous communications minister.
The authority maintains that tests showed progress over technologies used back in a 2005 trial. "The median rate of successful blocking was improved from the previous trial," it said.
The results were welcomed in some quarters, but some ISPs were guarded.
Child Wise chief executive Bernadette McMenamin said her child-protection organization supported the government's move to filter the Web, but only under strict guidelines.
"We totally support the federal government's filtering plans but it must not go beyond child pornography," McMenamin said. "If adult content gets blocked as well, that wouldn't work. As a child protection agency we want ISPs to block child pornography but not any other form of pornography."
ContentKeeper chief executive Geoff Wood said he feels that ISP-level filtering is only one facet of protecting children.
"Parents must also do all they can to keep their children safe on the Web," he said.