Making Decisions
The notion of a spherical cow appears here.
We feel that our model contains all the details relevant to decision-making…pursue it and see where it leads.
The model is a set of decisions with a set of events . Trying to formulate an exclusive and exhaustive list of both of these things is hard. But trying can produce some useful results.
The ‘Standard’
Chapter 2 is about a ‘numerical measurement’ for uncertainty. Lindley says that all measurements are in reference to a ‘standard’. To specify the size of your garden, you would use meters, a reference to the length of a path traveled by light in 1/speed of light seconds. A reference is a ‘grounding’, an agreed upon ‘source of truth’.
The communication of probability is whats important here. When someone says, I think this event will happen with a 70% probability. I can use the standard to get a sense of what that means. The ‘mental image’ is different for both agents but there is a common understanding.
In probability theory, the number ‘represents’ a belief in the happening of an event. This belief can then be felt by anybody by using the standard.
The way Lindley sees probability.
Probability expresses a relationship between a person and the world he is contemplating. Some have regarded this as a disadvantage. In fact, the subjective nature of probability is its great strength, for it describes a real situation of a subject, or observer, contemplating a world, rather than talking about a world divorced from the observers living in it, as do some other sciences. Recognizing that two observers. p.20