"I'd say from this World Cup, they are the form team so far, definitely. They were outstanding against England and showed how clinical they can be in that Wales match. It's going to be a huge test for us," Dickinson told reporters on Monday.
"There is no doubt we are going to be massive underdogs, but we can take confidence from that fact we've got out of a pretty tough group to reach the quarter-finals. We have nothing to lose. I don't think anybody expects Scotland to win this match."
Australia went through as Pool A winners after beating England and Wales at Twickenham on Saturday in a match in which they were reduced to 13 men for a spell during the second half but repelled intense Welsh pressure.
Dickinson said Scotland, Pool B runners-up behind South Africa, needed to find a way through a Wallabies defence which has conceded just one try in four games at the tournament.
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"It will be difficult. There's no doubt about it. We just have to be confident we can score but we know how difficult it's going to be," he said.
"It seems like they have built a brick wall across their line but we just need to look at what we've done in previous games and see if we can improve."
Scotland can take heart from winning two of their last three meetings, including a memorable 9-6 victory in Australia three years ago, their first since 1982, when Greig Laidlaw kicked a
penalty in time added on.
"We have got to go out there and impose ourselves on the game. It's going to take a huge performance from us, there's no doubt about that. But there's no reason why we can't go out there and do something special," Dickinson said.
(Reporting by Justin Palmer, editing by Ed Osmond)
