XLV. The purposes and functions of criteria

The word criteria and its singular, criterion, are additional entries in the list of terms that create ambiguity or confusion in modem clinical science. According to the definition in a conventional dictionary85, a criterion is a ‘standard, rule, or test by which something can be judged’. These three different nouns—the standard, the rule, and the test—refer to three distinct kinds of activity for the work that is done by criteria.