AI is not only being used to help decide on loans, insurance claims and job applications, it is also increasingly used in public functions, including in the justice system. For example, in the US courts and correction departments are using AI to aid decisions about bail, sentencing and parole. Yet these algorithms are often a "black box", meaning their inner workings are not known to the people using them, as they are proprietary pieces of software developed by someone else. If an algorithm is going to influence whether you get a mortgage, get a job interview, or – if you are in the unfortunate situation of having a brush with the law – whether you get bail or not, you would want to be sure its assessments are fair. This is impossible if the people using it (a bank, employer, court) have no idea how it works.

The technology industry is facing up to the world-shaking ramifications of artificial intelligence. There is now a recognition that AI will disrupt how societies operate, from education and employment to how data will be collected about people. Machine learning, a form of advanced pattern recognition that enables machines to make judgments by analysing large volumes of data, could greatly supplement human thought. But such soaring capabilities have stirred almost Frankenstein-like fears about whether developers can control their creations. Failures of autonomous systems -- like the death last yearof a US motorist in a partially self-driving car from Tesla Motors -- have led to a focus on safety, says Stuart Russell, a professor of computer science and AI expert at the University of California, Berkeley.