You are accused of a crime? Who would you rather decides your future - an algorithm or a human? Before making your decision, bear in mind that the algorithm will always be more consistent, and far less prone to an error of judgement. Then again, at least the human will be able to look you in the eye before determining your fate. How much fairness would you be willing to sacrifice for that human touch? This is just one of the dilemmas we face in the age of the algorithm, where the machine rules supreme, telling us what to watch, where to go, even who to send to prison. As increasingly we rely on them to automate big, important decisions - in crime, healthcare, transport, money - they raise questions that cut to the heart of what we want our society to look like, forcing us to decide what matters most. Is helping doctors to diagnose patients more or less important than preserving our anonymity? Should we prevent people from becoming victims of crime, or protect innocent people from being falsely accused? Hannah Fry takes us on a tour through the good, the bad, and the downright ugly of the algorithms that surround us. In Hello World she lifts the lid on their inner workings, demonstrates their power, exposes their limitations, and examines whether they really are an improvement on the human systems they replace.