History of the paradigm shift

Psychologist Jean Piaget saw children's development as a series of separate stages marked by periods of adjustments. Inspired partly by Piaget, Thomas Kuhn - a physicist, philosopher, and historian of science -proposed two kinds of scientific change:

• Incremental developments in the course of "normal science."
• Scientific revolutions that accentuate the more stable phases.

He proposed that scientific revolutions are not a matter of incremental progress; they involve "paradigm shifts."

The term paradigm can be used in many distinct senses. For example:

• A paradigm could refer to a special kind of achievement that draws an enduring group of adherents away from competing modes of scientific activity, but is open enough to leave all sorts of problems for the new group ...