When a paradigm guides a scientific field, nearly all research is considered in relation to that paradigm. Research is focused; the paradigm indicates which research topics are appropriate and worthwhile. Both theoretical and experimental studies are largely confined to three foci:
1) collecting data to test predictions of the paradigm;
2) pursuing aspects that may elucidate seminal phenomena. These investigations often require development of more sophisticated, more accurate equipment; and
3) attempts to ‘articulate’ the paradigm, including efforts to extend it and account for other phenomena, and attempts to resolve apparent problems or ambiguities.
Paradigm change is rare; working under a guiding paradigm is the norm. These ‘mopping-up operations’ are exciting because they promise goal-oriented, steady progress rather than a frustrating floundering. Often the results of experiments are readily predictable, but the work is still challenging. Ingenuity and insight are needed to determine how to conduct the experiment most successfully and elegantly.
Researchers ignore most data that appear to be unrelated to or unexplained by the paradigm. Moreover, we tend to ignore evidence that conflicts with the paradigm. No paradigm explains all observations, because no paradigm provides ultimate and final truth. Yet the immense explanatory power of the paradigm leads scientists to think of the contradictory data either as mistaken or as explicable by future elaborations of the paradigm. In either case, the results can be ignored for the moment -- or so we tell ourselves, if we even notice the contradictions. Publication of evidence that seems to conflict with the paradigm is hazardous, for the authors risk being branded as nonbelievers or outsiders.
An established paradigm is insulated from overthrow, by both the tendency to ignore discrepant facts and by the habit of refining hypotheses and paradigms [Kuhn, 1970]. Even when many anomalies are found, we do not discard the paradigm, for rejection leaves a vacuum. Rejection implies that all the predictive successes of the paradigm were coincidental. Only when a new potential paradigm appears will abandonment of the old be considered. Scientific inertia is conservative: a new paradigm is accepted only if it is demonstrably superior -- not merely equal in success -- to the old paradigm.
Timing of the new paradigm’s appearance is critical. It must be considered when anxiety over anomalies in the old paradigm is high. Without the leverage of anomaly anxiety, attempts to challenge the paradigm’s authority are likely to fail (e.g., Plato vs. democracy, Aristotle vs. slavery, Descartes vs. experimental science, and Einstein vs. quantum mechanics). Introduction of a new theory too early will encounter complacency with the old one. Indeed, sometimes the new paradigm is a reintroduction and slight refinement of a previously proposed idea, which had failed to gain momentum.
Discovery “commences with the awareness of anomaly (i.e., with the recognition that nature has somehow violated the paradigm-induced expectations), continues with extended exploration of the area of anomaly, [and] concludes when the paradigm has been adjusted so that the anomalous has become the expected.” [Kuhn, 1970]
Paradigm change begins with a single anomaly that cannot be ignored. Anomaly creates a sense of trauma or crisis, as we saw in the card-flashing experiment [Bruner and Postman, 1949] when
