In The Structure of Scientific Revolutions, an anomaly refers to an observation or phenomenon that contradicts the existing scientific paradigm. Anomalies play a pivotal role in Kuhn’s argument, serving as catalysts for crisis within the scientific community. When anomalies accumulate and resist explanation within the current paradigm, they become the driving force behind paradigm shifts and the initiation of revolutionary scientific thought.

Crisis, according to Kuhn, is a central concept signifying a breakdown in the normal problem-solving activities of scientists within a particular paradigm. A crisis occurs when anomalies challenge the existing theories and create a sense of dissatisfaction within the scientific community. This state of upheaval and uncertainty becomes the impetus for reevaluating and ultimately transforming the prevailing scientific paradigm.

In the context of The Structure of Scientific Revolutions, the term “cumulative” refers to the traditional view of scientific progress as a steady and additive accumulation of knowledge within a particular scientific paradigm. In a cumulative model of science, each new discovery, observation, or theory is considered to build upon and extend the existing body of scientific knowledge. This incremental process implies that scientific understanding evolves in a linear and continuous fashion, with each generation of scientists contributing to the growth of a coherent and expanding body of knowledge.