Manager Steve Eyre knows Rochdale must improve defensively if they are to haul themselves away from the bottom of League One.
A 4-2 defeat at newly-promoted Stevenage means Dale have just two points from their opening six league games.
"We were poor in the first half and slack defending was punished by a good Stevenage side," said Eyre. "We knew they'd be a threat in certain situations but lessons haven't been learned once again.
"I'm disappointed for the fans who travelled down here to watch our performance - it wasn't good enough and Stevenage made the most of their opportunities.
"We had a chance to get back into the game shortly after half-time but then we give them a very soft own goal and we're then right up against it at 4-1 down.
"We've got to keep working hard on the training ground until we get things right. It's been a tough first few weeks for me and the lads but we knew all along it would be as there are some real quality sides in this division."