In the 1920s began a period of so-called Neyman-Pearson inference. Bayesian inference re-emerged over the last 20-25 years and is now widely accepted.

Bayesian inference is based on simple principles - that conclusions must be logically consistent; that conclusions shall be based on what has been observed or what is already known; and that the results can be used as a basis for decision.

Since conclusions are to be based on everything that is known, two individuals with different background knowledge may draw different conclusions from the same experiment.

If an investigation or experiment is to be scientifically proven the data must be so extensive as to convince even individuals who, prior to the experiment, harbour reasonable doubt, given such individuals are open to rational debate.


Mattias Villani, professor