The apex of all tension for me is usually the day just before a test is to had.
Teachers recommend students for advanced placement according to how well they do on tests.
Students also achieve more in school if they feel that a teacher thinks that they are smarter than the other kids. Students are very aware of the behavior of instructors and if one feels that a teacher believes that he or she has a special ability then it is probably because that teacher does. So, tests determine how a teacher reacts to a student in some way. It could be recommending that student for advanced placement or just calling on him or her very frequently in class.