Various scientific methods tools :
1) 280 B.C.E. cataloged library with index (at Alexandria) - a way to serch recorded information.
2) 1403 Collaborative encyclopedia - a pooling of knowledge from more than one person.
3) 1590 Controlled experiment, used by Francis Bacon - wherein one changes a single variable in a test.
4) 1665 Necessary repeatability - Rober Boyle's idea that results of an experiment must be repeatable to be valid.
5) 1752 Peer-review-refereed journal - adding a layer of confirmation and validation over shared knowledge.
6) 1885 Blinded, randomized design - a way to reduce human bias; randomness as a new kind of information.
7) 1934 Falsifiable testability - Karl Popper's notion that any valid experiment must have some testable way it can fail.
8) 1937 Controlled placebo - a refinement in experiments to remove the effect of biased knowledge of the participant.
9) 1946 Computer simulations - a new way of making a theory and generating data.
10) 1952 Double-blind experiment - a further refinement to remove the effect of knowledge of the experimenter.
11) 1974 Meta-analysis - a second level analysis of all previous analysis in a given field.