A lot of people get confused when the plural of a word doesn't end in an "s." What's going on?
CRITERIA OR CRITERION?
"Criteria" is plural (like "phenomena"), while "criterion" is singular, like "phenomenon." You have one criterion or many criteria. It's easy to be confused, since some words (e.g., "data" and "media") are the same whether singular or plural.
Examples: Angela Allen Parker detailed the six basic criteria for accepting a client...The restaurant has one criterion for entry: every customer must wear shoes or sandals.