At an event in San Francisco, USA, IBM has presented an artificial intelligence (AI) system that can engage in reasoned arguments with humans on complex topics. Called Project Debater, the system was designed to debate around 100 topics, in a pre-determined debate format: a four-minute introductory speech, a four-minute rebuttal to the opponent's arguments, and a two-minute closing statement. Project Debater, trained in advance on debating methods, but not the details of the debates, relied on a collection of 300 million news articles and academic papers (previously indexed) to construct its case. While it was noted by several observers that some of the points made by the system were either quoting sources or merely reusing parts of articles, the system also tried to 'directly argue with points that its human opponents made, in nearly real time'. IBM explains on its website that Project Debater 'digests massive texts, constructs a well-structured speech on a given topic, delivers it with clarity and purpose, and rebuts its opponent'. The company estimates that, at the moment, the system could have a meaningful debate on the 100 topics it was designed for about 40% of the time. The overall objective of the project is to 'help people reason by providing compelling, evidence-based arguments and limiting the influence of emotion, bias, or ambiguity'.