Thousands of Twitter bots active during 2018 US mid-term elections

Scientists have identified thousands of Twitter bots, including those originating from Russia and Iran, that were active during the mid-term elections in the US last year, a study has found.

The study by researchers from University of Southern California in the US showed that more than a fifth of those posting about the elections on Twitter with #ivoted were robots.

Between October 6 and November 19, nearly two weeks after the election day, the researchers identified more than 200,000 bots posting about the mid-term elections, compared to about 750,000 humans.

The research provides more detail about interference operations that were found to originate within Iran, Venezuela and Russia, CNBC reported.

Thousands of those bots could be traced to Russia and several hundred could be traced to Iran, according to Emilio Ferrara, of USC's Information Sciences Institute.

Much of the bot activity appeared to originate in the US or had no clear provenance, Ferrara said.

To identify which accounts were bots, the researchers used a tool called the "Botometer" which uses machine learning techniques to determine whether an account is operated by a human or by a software algorithm.

Ferrara said the tool correctly designated an account about 95 per cent of the time.

The number of bots active in the 2018 elections appeared to represent a dramatic reduction compared to 2016, researchers said, possibly as a result of Twitter's efforts to remove bots from its platform.

However, the team warns that it is impossible to tell whether the reduction in bot activity since 2016 was the result of increased monitoring efforts or if the bots were becoming more sophisticated and avoiding detection.