What is a paradigm case?

A paradigm case refers to a typical example that effectively represents and defines the characteristics of an entire category or concept. This type of case serves as a standard or model, illustrating the essential features that members of the category share. For instance, when discussing the concept of a "bird," a sparrow or a robin often serves as a paradigm case because they embody the common traits associated with birds, such as feathers, the ability to fly, and the laying of eggs.

In contrast, the other options do not accurately capture the essence of what a paradigm case is. A controversial example challenges existing norms rather than illustrating a widely accepted standard. An abstract concept without real-world application does not provide any concrete examples to clarify a category. A rare instance that doesn't fit established rules fails to represent typical traits and thus does not meet the criteria for being a paradigm case. Therefore, the definition of a paradigm case as a typical member that defines an entire category is the most accurate choice.