Twitter recently began taking more steps to clean up spam and automated activity, and "close the loopholes they'd exploited," according to Harvey and Roth.
"We're also now automating some processes where we see suspicious account activity, like exceptionally high-volume tweeting with the same hashtag, or using the same @handle without a reply from the account you're mentioning," they said.
Twitter systems identified and challenged more than 9.9 million "potentially spammy or automated accounts" weekly in May, according to Harvey and Roth.
Twitter last month said that it was stepping up its long-running battle against online trolls, trying to find offenders by looking at "behavioral signals." The new approach looks at behavioral patterns of users in addition to the content of the tweets, allowing Twitter to find and mute online bullies and trolls.
Even if the offending tweets are not a violation of Twitter policy, they may be hidden from users if they are deemed to "distort" a conversation, Twitter said.
Twitter already uses artificial intelligence and machine learning in this effort but the latest initiative aims to do more by focusing on the actions of certain users in addition to the content.
Twitter is among online platforms under pressure to do more to safeguard against being used to spread misinformation or promote division, as proved the case during the US presidential election in 2016, in which US intelligence says Russia meddled to help Donald Trump win.