Abstract: The answer is the likelihood principle.

*This will review the state of the art, and say why it's so important.*

Every philosopher knows the Principle of Total Evidence, usually associated with Carnap, which says that one should not ignore information.

"A principle which seems generally recognized,[footnote 10: Keynes, op. cit.[J.~M.~Keynes, \it A Treatise on Probability\/ (1921)], \p.313, refers to `Bernoulli's maxim, that in reckoning a probability, we must take into account all the information which we have'.] although not always obeyed, says that if we wish to apply such a theorem of the theory of probability to a given knowledge situation, then we have to take as evidence $e$ the \it total evidence\/ available to the person in question at the time in question, that is to say, his total knowledge of the results of his observations." \cite[p\p.138—139]Carnap:1947

"Bernoulli's maxim,[footnote 1: \it Ars Conjectandi, \p.215: `Non sufficit expendere unum alterumve argumentum, sed conquirenda sunt omnia, quae in cognitionem nostram venire possunt, atque ullo modo ad probationem rei facere videntur.'] that in reckoning a probability we must take into account all the information which we have" \cite[\p.313]Keynes:1921

—-

The likelihood principle is a version of this applicable to statistical inference. It says (roughly) that when one has a sample of data, one should take that sample fully into account when making inferences about hypotheses. And yet, because of the popularity of evaluating methods of inference on their long-run behaviour, the likelihood principle is frequently broken.

—-

This could emphasise the role of the LP in

**categorising**theories of statistical inference. I don't think anyone's really made a big deal about that yet. B&W's book doesn't do that: they want to push Bayesianism. And the other books want to push the use of raw likelihoods or raw likelihood ratios.where can I publish such a long paper? or should it be just a summary?

note to self: say something about 'the importance of protocol' in Hutchison BJPS, Dowe, Korb etc.