The Art of Statistics: Learning from Data

by David Spiegelhalter

What Is a ‘Hypothesis’? A hypothesis can be defined as a proposed explanation for a phenomenon. It is not the absolute truth, but a provisional, working assumption, perhaps best thought of as a potential suspect in a criminal case. When discussing regression in Chapter 5, we saw the claim that observation = deterministic model + residual error. This represents the idea that statistical models are mathematical representations of what we observe, which combine a deterministic component with a ‘stochastic’ component, the latter representing unpredictability or random ‘error’, generally expressed in terms of a probability distribution. Within statistical science, a hypothesis is considered to be a particular assumption about one of these components of a statistical model, with the connotation of being provisional, rather than ‘the truth’.

Hypothesis is provisional causation