Brad reads Popper

"But it's under .05!" 2013-03-15

I’m finding important contrasts between The Logic of Scientific Discovery and my fourth-hand preconceptions of the book. Popper differentiates between four kinds of tests:

“the logical comparison of the conclusions among themselves, by which the internal consistency of the system is tested”
“the investigation of the logical form of the theory, with the object of determining whether it has the character of an empirical or scientific theory”
“the comparison with other theories, chiefly with the aim of determining whether the theory would constitute a scientific advance should it survive our various tests”
“the testing of the theory by way of empirical applications of the conclusions which can be derived from it”

Statistics is largely concerned with the last of these, and so it should be. But it’s worth reminding ourselves and JPSP editors that the first three kinds of tests exist and are worth doing.

The demarcation problem — “finding a critierion which would enable us to distinguish between the empirical sciences on the one hand, and mathematics and logic as well as ‘metaphysical’ systems on the other” — is something I think about a lot. I hadn’t previously connected this to the induction problem, and will have to think about whether accepting a convention for demarcation lets us build science without induction.

Popper says that scientific statements are objective in the sense that they can be criticised “inter-subjectively”. In practice this seems to mean that other scientists can test the statements. This means “there can be no ultimate statements in science”, which I am satisfied with.