The term paradigm describes a set of assumptions, concepts, values, and practices that constitute a way of viewing the world for the community that shares them, especially in an intellectual discipline.1 The term paradigm shift is used to describe a fundamental and major transformation in the established paradigm of a community.
The term paradigm shift first derives from the work of Thomas Kuhn in his study of how scientific assumptions and theories change over time through a nonlinear process. Since the 1960s, the concept of a paradigm shift has also been used in numerous non-scientific contexts to describe a profound change in a fundamental model or perception of events.2 In this more general sense, the term paradigm means the cognitive framework, pattern or model from which people operate.
In 1962 a man named Thomas S. Kuhn published a book called the Structure of Scientific Revolutions. The idea for the book arose while he was studying for his Ph.D. thesis. He read through the history of science and noticed that the standard account of its history did not do justice to the complexity of its situation. In this standard account, science was being portrayed as a slow and steady progression towards ever greater knowledge in a linear fashion, with current discoveries just being layered on top of past ones in a somewhat linear accumulation over time. Kuhn went on to develop an alternative nonlinear model to the development of scientific knowledge where normal periods of stable development are punctuated with revolutionary transformation as the paradigm fails, and new theories are developed, compete and ultimately come to replace the old framework.
Kuhn noticed that within a particular scientific domain when the science claimed to be based solely on facts, there were always some facts that are seen as being more important than others. Certain problems and issues arise within a particular domain and before long the area becomes shaped around those questions, certain assumptions form and frameworks develop to help structure people’s reasoning. Kuhn called this overarching way that we look at the field of inquiry a paradigm. As new people become indoctrinated within a particular area, they become imbued with that paradigm and ultimately dependent upon it to structure their thinking about the subject.
As the paradigm becomes established it becomes this shared model that shapes what questions get asked and how facts are seen. Kuhn put forward the idea that there are three fundamentally different modes or stages in the development of a science depending largely on the state of the central paradigm used within that science. These stages are Pre-Science, where no paradigm yet exists, Normal Science, where an accepted and established paradigm guides inquiry, and Revolutionary Science where the central paradigm is called into question and new contenders compete to form a new central model.3
Kuhn noticed that a science is not merely born fully fledged but that they go through a pre-scientific stage of formation. Pre-Science is characterized by a lack of agreement, constant debate over fundamentals and thus a lack of paradigm with which to proceed as a unified community. Pre-scientific domains are not really scientific at all; they are philosophical in nature as they go through a process of basic ontological development, i.e. trying to define what exactly it is they are studying and what is the best approach to trying to tackle it, with wide scope for subjective interpretation and a diversity of perspectives.
During the normal period of development, researchers operate within an established and accepted theory and set of methods tackling what are seen to be legitimate questions within that paradigm. A good example of this would be 18th and 19th-century physics where Newtonian mechanics was the established paradigm that got applied to understanding everything from electricity to heat and all forms of motion. Kuhn writes in one essay “Normal Science means research firmly based upon one or more past scientific achievements, achievements that some particular scientific community acknowledges for a time as supplying the foundation for its further practice.”
Most sciences, most of the time are not in a state of significant change and can thus be said to be in a normal stage of development marked by incremental improvements on previously established frameworks. This established paradigm is largely accepted and productive in delivering new insight into the issues that are taken as being important. Science in this normal stage is a highly conservative activity, the objective is to solve puzzles with limited alteration to the paradigm. Normal scientists are not trying to test the paradigm, in contrary, they accept it unquestioningly. One famous expression of this normal scientific stage within physics is given by Lord Kelvin in a speech in 1900 wherein he famously told an assemblage of physicists at the British Association for the Advancement of Science, “There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.”4
A scientific revolution occurs, according to Kuhn, when scientists encounter anomalies that cannot be explained by the universally accepted paradigm within which scientific progress has thereto been made.5 Over time anomalies are discovered, phenomena that simply cannot be reconciled with the existing paradigm. As more and more anomalies accumulate a burgeoning sense of crisis envelopes the scientific community. Confidence in the normal paradigm breaks down and the process of normal science grinds to a halt as it moves into a crisis, with this crisis marking the beginning of a period of revolutionary science.6
Finally out of the struggle to form a new model of understanding one or more viable candidates emerges. This begins the model revolution step. It is a revolution because the new model is a new paradigm. It’s radically different from the old paradigm, so different that Kuhn declared that the two are incommensurate. Each uses its own set of rules to judge the other. Thus believers in each paradigm find it difficult or even impossible to communicate.
Once a single new paradigm is settled on by a few significant and influential proponents, the paradigm change step begins. Here the field transitions from the old to the new paradigm while improving the new paradigm to maturity. Eventually, the old model is sufficiently replaced and becomes the field’s new Normal Science. The cycle then begins all over again, often with a prolonged stable or normal phase before a relatively short nonlinear revolutionary period.
The term paradigm also means a set of linguistic items that form mutually exclusive choices in particular syntactic roles.7 In this sense, a paradigm defines a certain lexicon and syntax for a particular area that shapes how we see it. For example in the English language we can say “a book” or “his book” but not “a his book.” This is an example of two paradigms or patterns that are not compatible, which helps to illustrate why paradigm shifts are seen to be major structure transformations. Because often the former and later patterns are incompatible. For example, when it comes to encoding information everyone can use analog or digital, but we will not be able to efficiently exchange information between a digital and analog device. Thus it makes sense to follow just one paradigm at any given time.