Extensional

Relating to or dealing with the extension or range of a term or concept; focused on the things or objects that a term applies to, rather than the term's meaning or intension. It concerns the specific members of a class or set defined by a term. In logic and semantics, an extensional definition is one that defines a concept by listing all its members. Essentially, it emphasizes the 'what' rather than the 'why' or 'how'. This contrasts with intensional definitions, which focus on the attributes or properties that define a concept.

Extensional meaning with examples

• The botanist's extensional approach to identifying trees involved listing every species found within the Redwood National Park. The definition focused solely on the specific trees, their geographical location, and their measurable characteristics, without delving into their evolutionary relationships or ecological roles. This data-driven method proved crucial for a comprehensive survey.
• In programming, an extensional understanding of a data structure like a list would involve seeing the items actually stored in the list. Thinking extensionally means visualizing the data the list contains, like a list of names 'Alice', 'Bob', 'Charlie', 'David', rather than focusing on its abstract properties as a data structure.
• The art critic assessed the exhibition extensionally, cataloging each painting by its creator, size, and the museum displaying it, thereby creating a complete, though somewhat superficial, record. There was no discussion about themes or how each painting was inspired. The list of each exhibit was all that mattered.
• When learning a new language, focusing on extensional vocabulary allows you to memorize specific words and their corresponding objects or concepts (e.g., 'dog' refers to a specific animal). You will know all of the words that translate into specific terms. The goal is to rapidly build a basic but functional vocabulary