It is now possible to predict who the best candidate for receiving an organ transplant is, know whether clients of a bank will return the loans they request, choose the films that best coincide with the interests of consumers, or even select someone’s ideal partner. Mathematical algorithms constantly analyse millions of items of data, identify patterns and make predictions about all areas of life. But in most cases, the results give little more than a closed prediction that cannot be interpreted and which is often affected by biases in the original data.