Definition

Definition

A definition is a statement of the meaning of a concept.

Generic relations

Superordinate concepts is:

• Statement

Subordinate concepts are:

• Intensional definitions
• Extensional definitions

Characteristics

• Appropriateness
• Circularity
• Clarity
• Conciseness
• Level of acceptance
• Unambiguity

Rules

Rules for a definition are:

1. What it is. A definition is composed of a statement explaining what the concept 'is', not what it refers to, describes or has. The word 'is' is put in front of a definition. Correct: An apple tree is a tree.... Incorrect: An apple tree refers to a tree...
2. Concept model. A definition reflects the concept model describing the concept and its relations to other concepts in the model. The characteristics used in the definition should therefore be selected to indicate the connection between the concepts or the delimation that distinguish one concept from another. Correct: An apple tree is a tree that bears apples. Apple tree is a subordinate concept of a tree and both concepts are part of a concept model.
3. Brief | Complex. A definition is as brief as possible and as complex as necessary. Additional information is included in a note. Incorrect: An apple tree is tree that bears apples with the purpose of being harvested.
4. Substitution. A definition can replace a term in a text without loss of or change in meaning.
5. Uncircular. A defintition is not circular. Incorrect: A chair is a chair on which you can sit.
6. Broad. A defintion is not too broad. Incorrect: An apple tree is a living organism.
7. Narrow. A definition is not too narrow. Incorrect: An apple tree is a tree that bears Golden Delicious apples.
8. Positive. A definition is positive (not negative). A definition describes what it is, not what it is not. Incorrect: An apple tree is not a pear tree.
9. Clarity. A definition is readable, unambiguous and written in proper language.
10. Generally accepted. A definition corresponds with a generally accepted understanding of the meaning of the term.

References

ISO 704 (2000). Terminology work - Principles and methods.