Criteria

Criteria are standards or principles by which something may be judged, decided, or classified. The term is the plural of criterion; singular form criterion is used for one standard. Criteria should be clearly defined to enable consistent evaluation.

In practice criteria appear in many contexts: eligibility criteria for programs; selection criteria for candidates; quality criteria for products; safety criteria for systems; performance criteria for tasks. They help organize evaluation, communicate expectations, and justify decisions.

Good criteria are objective when possible, verifiable, unambiguous, and comprehensive, covering all important aspects while avoiding unnecessary overlap. They are often organized as a rubric, checklist, or scoring system; they may be weighted to reflect priorities. In research, criteria define inclusion and exclusion; in decision making, they guide choice and comparison among options.

Etymology and usage: from Greek kritērion "a means of judging," via Latin criterion. In formal writing, the singular criterion refers to one standard, while criteria is the standard plural. Some contexts use criteria as a generic term, but traditional grammar keeps criterion for a single standard and criteria for multiple standards.