The paradigm concept is the idea that in any field there is a set of assumptions shared by those in the field. The paradigm defines the field and shapes the rules of the game. The concept was introduced by Thomas Kuhn in The Structure of Scientific Revolutions (1962).

A paradigm determines what gets taught and studied, the methods, and how the findings are interpreted. It defines the needs addressed, who is served, and how the services are provided. A paradigm supplies "all the answers" to researchers' and practitioners' questions.

A paradigm becomes self-sustaining. It provides continuity and stability. Its tenets are defended and change is resisted. It becomes more complex and encompassing, but does not evolve. Paradigms only change through radical and sudden shifts. These occur when new discoveries, knowledge, or concepts arise which cannot be rejected or assimilated by the old paradigm. The new paradigm supercedes the old paradigm.

1962, Thomas Kuhn published a groundbreaking book entitled The Structure of Scientific Revolutions. In it, he argued that the progress of science is not gradual but (much as we now think of biological evolution), a kind of punctuated equilibrium, with moments of epochal change.

When Copernicus explained the movements of the planets by postulating that they moved around the sun rather than the earth, or when Darwin introduced his ideas about the origin of species, they were doing more than just building on past discoveries, or explaining new experimental data. A truly profound scientific breakthrough, Kuhn notes, "is seldom or never just an increment to what is already known. Its assimilation requires the reconstruction of prior theory and the re-evaluation of prior fact, an intrinsically revolutionary process that is seldom completed by a single man and never overnight."[1] Kuhn referred to these revolutionary processes in science as "paradigm shifts", a term that has now entered the language to describe any profound change in our frame of reference.

Paradigm shifts occur from time to time in business as well as in science. And as with scientific revolutions, they are often hard fought, and the ideas underlying them not widely accepted until long after they were first introduced. What's more, they often have implications that go far beyond the insights of their creators.

http://tim.oreilly.com/opensource/paradigmshift_0504.html

See also:
The Vision Thing - Why people don't understand