Facebook has admitted there's some work to be done on its newsfeed algorithms, after fake news stories were being promoted as real during the US election.
But chief executive Mark Zuckerberg has dismissed the idea that it could have influenced voters as "crazy".
Donald Trump's victory in the presidential election defied polls and expectations, and some blame for the shock has been put on the "echo chamber" of social media - where people are only seeing opinions they agree with and not any opposing ones.
On social media, and on Facebook in particular, several fake news stories appeared in people's newsfeeds alongside real ones, making it harder to distinguish information from misinformation.
Fake stories were also appearing in the website's "Trending Topics" section, and it worsened once the company fired its human selectors in favour of the algorithms.
Buzzfeed discovered that a number of these stories were being generated by teenagers in Macedonia.
In a statement to TechCrunch, Facebook's VP of product management, Adam Mosseri, admitted there's more than can be done to fight this growing issue.
"We take misinformation on Facebook very seriously. We value authentic communication, and hear consistently from those who use Facebook that they prefer not to see misinformation."
He says in both the newsfeed and the trending section, they work to ensure "the topics being shown are reflective of real-world events" and reduce the distribution of misinformation.
"Despite these efforts we understand there's so much more we need to do, and that is why it's important that we keep improving our ability to detect misinformation," Mr Mosseri said.
But Mr Zuckerberg says it's a "pretty crazy idea" to suggest the misinformation on the site could have influenced voters.
"There is a profound lack of empathy in asserting that the only reason someone could have voted the way they did is because they saw fake news," he said at a conference on Thursday (local time).
Mr Zuckerberg also rejected the idea that Facebook, and other social media, has created an echo chamber.
He says most users will have friends who have different political views to each other, and Facebook friends often cross states and countries.
"That means that the information you are getting through the social system is going to be inherently more diverse than you would have gotten through news stations," he said.
Either way, Mr Mosseri has promised more will be done to prevent the spread of fake news.
"We're committed to continuing to work on this issue and improve the experiences on our platform," he said.