Statistics

Statistics is the science of collecting, summarising, and drawing conclusions from data while honestly accounting for uncertainty. Its central idea is that we usually cannot measure everything, so we must reason carefully from a limited slice of the world.

Statistics gives data science its backbone: it provides the rules for what a number actually tells you and how confident you are allowed to be. For example, if a survey of 1,000 voters shows a candidate at 52 percent, statistics tells you how far the true figure for all voters might plausibly be from that estimate. Without it, it is easy to be fooled by random noise and mistake a fluke for a real effect.