The trio felt there were positives to take out of Friday's first World Cup pool stage loss for New Zealand in 32 matches going back to 1987, even if it did leave them in unfamiliar territory.
"It's a different one, we haven't been in this situation before and that's something that we're going to have to address going forward," lock Whitelock, a World Cup winner in 2011 and 2015, told reporters after the match.
"I thought we started pretty well. So there's some really good things to take out of the week, (but) the biggest thing would be we gave away a few too many penalties.
"Everyone's got to understand what we're trying to do and understand how the referees are refereeing. Just making sure that we're squeaky clean and not giving the opposition (a) free opportunity."
Full back Barrett, who was part of the 2015 title-winning team, said the 27-13 defeat was a blow but made little difference to what New Zealand needed to do in their last three Pool A matches.
"Funnily enough, it won't change much when it comes to earning the right to be in a quarter-final. We're all aware of that path and that route," he said.
"What we've got to take from this game is the learnings but also keep believing because we did a lot of good things out here tonight."
Smith, another member of the 2015 champion side, said good discipline was even more important when facing teams with place kickers like France's Thomas Ramos (28).
"We've just got to keep our chins high. We're still All Blacks, we're still proud of who we are and what we are," he said.
"You can't give away penalties with Ramos able to kick from 50 to 55 metres, he nails most of them, so it's a good lesson for us but there's plenty of positives here.
"If we're at the right end of the park, we showed what we can do. And we showed how dangerous we are on the break so that's what we'll be going for next week."
