We may be interested in some facet of the real world, for example how much faster it is to use one system compared with another. However, we typically only have some sort of partial or noisy measured data. Probability theory can help us to assess the likelihood of the measurement given the state of the world. However, we do not know the real state of the world, only the measurement. The job of statistics is to reverse this, to create some sort of estimate of, or knowledge about, the real world from the measurement. Because the measured data is subject to random effects, the knowledge we obtain from statistics will always be uncertain.

Defined on page 4

Used on pages 4, 5, 8, 15, 57, 58, 59, 71, 105

Also known as job of statistics