According to Thomas Kuhn and Paul Feyerabend, is science characterized by incommensurability?

The term incommensurable comes from the Greek for having no common measure and originated in the field of mathematics. As applied in science, theories are commensurable if they can be directly compared to determine which is more valid or useful. The theories must share a common conceptual framework and nomenclature in order to be compared. This concept basically means you must compare apples to apples, oranges to oranges. Theories are incommensurable if they cannot be directly compared because they have drastically different conceptual frameworks or nomenclature—comparing apples to oranges.

Paul Feyerabend first presented his explanation of commensurability in 1952. He identified three principle reasons scientific theories may be incommensurable. First, observations are essentially influenced by the theoretical assumptions of the observer, so theory can never be teased out from observation. Second, paradigms have different underlying assumptions about scientific methods and building scientific knowledge. Third, new theories give rise to new language, meaning competing theories cannot be directly compared because they are, in effect, different languages.

Thomas Kuhn applied the philosophical concept of commensurability to the field of science in his 1962 book The Structure of Scientific Revolutions. He posited that, historically, competing paradigms organize concepts differently, leading to communication problems in comparing these differing views. Like Feyerabend, Kuhn pointed to language as a fundamental issue creating incommensurability.