The rise of Big Data and algorithms is changing all of this. Vast collections of data and what are known as machine learning techniques allow for vast numbers of decisions to be automated. Algorithms or artificial intelligence can be more efficient, less expensive, and – if well-designed – more accurate than humans. Therefore, it is unsurprising that we are increasingly replacing human decision-makers with decision-making algorithms, and that they are now increasingly deciding if we get hired, fired, or are sent to prison.

Algorithms, however, are often highly complex and opaque, difficult to scrutinise, and can make biased and discriminatory decisions. On Tuesday, it was reported that Facebook aborted an experiment because two robots began communicating with each other in a language only they could understand. The reality was more complex, but the case raises a crucial question: If artificial intelligence is capable of thinking in ways we can’t comprehend, how accountable can it be?