Normal science, identified and elaborated on by Thomas Samuel Kuhn in The Structure of Scientific Revolutions,[1] is the regular work of scientists theorizing, observing, and experimenting within a settled paradigm or explanatory framework.
Prior to the formation of a shared paradigm or research consensus, would-be scientists were reduced to the accumulation of random facts and unverified observations, in the manner recorded by Pliny the Elder or Francis Bacon,[4] while simultaneously beginning the foundations of their field from scratch through a plethora of competing theories.
[7] Scientists derive rules from paradigms, which also guide research by providing a framework for action that encompasses all the values, techniques, and theories shared by the members of a scientific community.
When astronomers use special telescopes to verify Copernican predictions, they engage the second class: the matching of facts with theory, an attempt to demonstrate agreement between the two.
The normal scientist presumes that all values, techniques, and theories falling within the expectations of the prevailing paradigm are accurate.
[16] In this way however, according to Kuhn, normal science possesses a built-in mechanism that ensures the relaxation of the restrictions that previously bound research, whenever the paradigm from which they derive ceases to function effectively.
Kuhn's normal science is characterized by upheaval over cycles of puzzle-solving and scientific revolution, as opposed to cumulative improvement.
Imre Lakatos has accused Kuhn of falling back on irrationalism to explain scientific progress.
[20] Lakatos evaluates problem shifts, changes to auxiliary hypotheses, by their ability to produce new facts, better predictions, or additional explanations.