15 Quotes by Douglas W. Hubbard

If a measurement matters at all, it is because it must have some conceivable effect on decisions and behaviour. If we can't identify a decision that could be affected by a proposed measurement and how it could change those decisions, then the measurement simply has no value

Essentially, all models are wrong, but some are useful.

A problem well stated is a problem half solved.

Myth: When you have a lot of uncertainty, you need a lot of data to tell you something useful. Fact: If you have a lot of uncertainty now, you don’t need much data to reduce uncertainty significantly. When you have a lot of certainty already, then you need a lot of data to reduce uncertainty significantly. In other words – if you know almost nothing, almost anything will tell you something.

Understanding how to measure uncertainty is key to measuring risk. Understanding risk in a quantitative sense is key to understanding how to compute the value of information. Understanding the value of information tells us what to measure and about how much effort we should put into measuring it.

Measurement: A quantitatively expressed reduction of uncertainty based on one or more observations.

Rule of Five There is a 93.75% chance that the median of a population is between the smallest and largest values in any random sample of five from that population.

It is better to be approximately right than to be precisely wrong. – Warren Buffett.

Instead of being overwhelmed by the apparent uncertainty in such a problem, start to ask what things about it you do know.