Evaluation

Evaluation is the process of coming to a judgment about how good something is. A list of standards (a criteria) needs to be created before the judgment is made. This list defines what 'good' looks like in that situation. Whatever is being judged is then compared to this list. A judgment can then be made about how good that thing is.
Use in education.
Students are regularly evaluated in schools and universities to decide how good they are. Teachers may create a list of standards that a student must reach in order to pass a course. To be fair, this list must be applied consistently and equally to all students. 
In some subjects, students may write essays. An essay is a long piece of writing that includes evaluation. Therefore, the introduction of an essay usually includes a judgment about how good something is and the list of standards that the student has used to make that judgement. The remainder of the essay is spent proving that the opinion formed is logically correct. The writer of the essay may return to the criteria frequently to demonstrate that their opinion is the correct one, given the criteria they have used.