Between nine and 15 percent of active Twitter accounts are autonomous entities known as social bots, new research has found. The micro-blogging site has a little over 300 million monthly active users and that would mean nearly 27 million to 45 million accounts are actually not controlled by humans, according to the study. The researchers from Indiana University and University of Southern California in the US wanted to find out how much of the content on Twitter is generated by bots. “Our estimates suggest that between nine per cent and 15 percent of active Twitter accounts are bots,” the researchers said. To detect bot accounts on Twitter, the researchers analysed publicly available data about user’s friends, Tweet content and sentiment, network patterns, and activity time series. “Characterising ties among accounts, we observe that simple bots tend to interact with bots that exhibit more human-like behaviour,” the study said. The Twitter bot detection framework that the researchers developed leverages more than one thousand features to evaluate the extent to which a Twitter account exhibits similarity to the known characteristics of social bots. “Our models yield high accuracy and agreement with each other and can detect bots of different nature,” the researchers said. According to the researchers, many bots also “perform useful social functions such as dissemination of news and publications and coordination of volunteer activities” – but there is a dark side, too, as they can support “malicious applications” like promoting terrorist propaganda and recruitment, Cbsnews.com reported.