Vagueness

The term vagueness denotes a property of concepts (especially predicates). A concept is vague:

• if the concept's extension is unclear;
• if there are objects which one cannot say with certainty whether belong to a group of objects which are identified with this concept or which exhibit characteristics that have this predicate (so-called "border-line cases");
• if the Sorites paradox applies to the concept or predicate.

In everyday speech, vagueness is an inevitable, often even desired effect of language usage. However, in most specialized texts (e.g., legal documents), vagueness is distracting and should be avoided whenever possible.