the better than average effect (illusory superiority).
Explanation:
Based on the information provided within the question it can be said that this is an example of the better than average effect (illusory superiority). This is a cognitive bias where an individual overestimates their own qualities and abilities in comparison to the rest of the population who possess those same qualities or abilities.
A Grading Schema is a mapping of percentage ranges to a specific grade display. When a Grading Schema is employed (depending on the grade), the Grade Center will translate the percentage score and display the corresponding value based on the schema.