To Thomas Kuhn, scientific progress is made in a cumulative process which starts as a revolutionary idea – a “new paradigm” – and matures into what Kuhn terms “normal science”. Scientific disciplines should therefore aspire toward normal science, which aims mostly at gathering data, and forming highly-detailed hypotheses which are consistent with the revolutionary paradigm – the new idea – upon which that particular scientific discipline was founded.
For example, the work of modern microbiologists is very specialized. Some microbiologists work on analyzing only one virus throughout their careers, and in fact, usually more specific than that, they might study only the protease (a specific section of the DNA) in a specific virus. This extreme specialization allows for tons of data to be gathered by the scientific community, and with the use of peer-reviewed journals, this data can be shared for many practical applications. But this highly-detailed modern version of microbiology is based on the relatively radical and generalized work of people like Louis Pasteur.
Pasteur’s scientific revolution—his “new paradigm”—was the establishment of the existence of microbes and the proposal that they could play a part in many diseases. Pasteur’s original discoveries about microbes did not involve much detail at all. The science of microbiology was, at Pasteur's time, immature. Over time, though, momentum was gained in the study of microbes, and as new details were discovered, even tinier details became attainable. Indeed, Pasteur himself would likely be baffled by modern microbiology and the detailed knowledge which has been made possible by the groundwork laid in his discoveries.
Normal sciences, in Kuhn’s view, should spend very little time revisiting or critiquing fundamental concepts or “facts” which have already been “established”. This set of established facts, along with its attendant norms relating to methods of data gathering, analysis, and other customs, comprise (in this instance) a “paradigm.” It is through this narrowed focus built upon a previously-radical “paradigm” that scientific progress is achieved.
That is, according to Kuhn in his The Structure of Scientific Revolutions, until such time as a “growing sense” manifests in the scientific community “that an existing paradigm has ceased to function adequately.” When such a sense grows large enough to reach its critical mass, a scientific revolution is born, and the “older paradigm is replaced in whole or in part by an incompatible new" paradigm.