Some news organizations are killing their comment sections entirely. And some are opening up the floodgates.

The Washington Post gets about a million comments every month on its stories, said Greg Barber, director of digital news projects at the newspaper. So, like The New York Times, The Post has begun using artificial intelligence and machine learning to moderate them.

ModBot, a new tool built by The Post's engineering team, filters new comments by referring to a record of decisions made by human moderators. It uses technology that deconstructs comments into their component parts and scores them against The Post's discussion policy.

To "train" ModBot's algorithm, engineers sent "conflict" comments — comments where human moderators and the algorithm disagreed — to a moderator for review. Then, those comments were fed back into ModBot for future reference.

"With each decision that was made, the algorithm got smarter, which is one of the exciting parts about it," Barber said.

In this way, ModBot is similar to Perspective, a similar tool from Alphabet's Jigsaw division that scores comments based on their toxicity. The New York Times has begun deploying a version of Perspective, called Moderator, to help screen 12,000 comments per day.

The Post began using ModBot to screen a "relatively low" number of comments but has been slowly increasing the number it screens, Barber said. Eventually, the newspaper hopes to use ModBot to surface exceptional comments that might be featured with stories, or in "Read These Comments," The Post's weekly newsletter featuring highlights from the comments section.

The Post has a team of moderators on contract through a third-party vendor that handles most of the moderating, Barber said. The majority of the moderators' time is spent on deciding which borderline comments should be approved, not which should be deleted outright. Simple rules against profanity and defamatory speech make those decisions easy.

ModBot has begun to help decide which comments should be waved through, and ultimately, Barber said, the tool will be used to help The Post engage more deeply with its readers.

"We don't want to engage less, we want to engage more," Barber said. "We want to spend more time with our readers — and we've got a lot of them — who come to The Washington Post to contribute really thoughtful feedback, or to propose their own ideas. A service like ModBot allows us to do that."