According to a recent research, more than four times as many tweets were made by automated accounts in favor of Donald Trump around the first presidential debate as by those backing rival Hillary Clinton.
The study found Donald Trump would have enjoyed more support on Twitter even if the accounts – known as bots – had not been active.
However, the research highlights that the software has the capacity to “manipulate public opinion” and “muddy political issues”.
The report has yet to be peer-reviewed.
One critic noted that it was impossible to be completely sure which accounts were real and which were “web robots”.
The research was led by Prof. Philip Howard, from the University of Oxford, and is part of a wider project exploring “computational propaganda”.
The investigation covered tweets posted on September 26, the day of the debate, plus the three days afterwards, and relied on popular hashtags linked to the event.
First, the researchers identified accounts that exclusively posted messages containing hashtags associated with one candidate but not the other.
These accounted for about 1.8 million pro-Trump tweets and 613,000 pro-Clinton posts.
The researchers then analyzed which of these had been posted by bots. They identified an account as such if it had tweeted at least 50 times a day across the period, meaning a minimum of 200 tweets over the four days.
The results suggested that 32.7% of such pro-Trump tweets had been posted by bots and 22.3% of such pro-Clinton ones.
In total, that represented a total of 576,178 tweets benefiting Donald Trump and 136,639 in support of Hillary Clinton.
Prof. Philip Howard said: “On the balance of probabilities, if you pulled out a heavily automated account the odds are four to one that you’ll find it’s a bot tweeting in favor of Trump.”
There is no suggestion, however, that bots were generated by either of the official Presidential campaign groups.
“We are not looking at the source, who is working on the bots or to what end, merely the metrics of the data,” said Prof. Philip Howard.
Looking wider – to accounts that tweeted neutral hashtags or a mix of different kinds – the study suggested that 23% of all the tweets were driven by bots.
One machine learning expert cautions that the criteria used to identify the bots might have been too imprecise to have sifted out all the human-based activity.
So, is it possible that Donald Trump supporters might simply have been more enthusiastic than Hillary Clinton’s and have done a better job at leveraging social media to their advantage?
Prof. Philip Howard said that it is unlikely to be the only explanation.
“Most of the heavy automation and tweets happened overnight and shared similar hashtags and information,” he says.
“They show behavior that is not human and often don’t have comments [about other issues apart from] the particular topic in question.”
Prof. Philip Howard adds that the 50-tweets-a-day rule was borne out by analysis of posts made during a past Venezuelan election and the Brexit vote.
In both cases, his team double-checked a sample of accounts that had been flagged as bots and confirmed they displayed other characteristics of being inhuman.