Why "each criteria" needs its own singular story

What kind of error is it?

Grammatical error related to countable and uncountable noun usage

Why do people make this mistake?

The confusion typically arises because people don't recognize "criteria" as the plural form. They may incorrectly think it's singular, akin to how "data" is often incorrectly treated as singular.

What is correct?

"Criteria" is the plural form, so it should be paired with plural terms like "each of the criteria" or use the singular form "criterion" if referring to one.