Bayesian Statistics the Fun Way

2MEASURING UNCERTAINTY

In Chapter 1 we looked at some basic reasoning tools we use intuitively to understand how data informs our beliefs. We left a crucial issue unresolved: how can we quantify these tools? In probability theory, rather than describing beliefs with terms like very low and high, we need to assign real numbers to these beliefs. This allows us to create quantitative models of our understanding of the world. With these models, we can see just how much the evidence changes our beliefs, decide when we should change our thinking, and gain a solid understanding of our current state of knowledge. In this chapter, we will apply this concept ...