criteria

Synonyms:
measure, touchstone, yardstick. See standard.

Usage note:
Like some other nouns borrowed from the Greek, criterion has both a Greek plural, criteria, and a plural formed on the English pattern, criterions. The plural in -a occurs with far greater frequency than does the -s plural: These are the criteria for the selection of candidates. Although criteria is sometimes used as a singular, most often in speech and rather infrequently in edited prose, it continues strongly in use as a plural in standard English, with criterion as the singular.