Second, we notice that accuracy rates for some classes are extremely high, which is mainly the case of classes of well-defined semantics (for example, University policies determine that a 5.0 grade should be considered average, and this kind of knowledge was taken into account by the domain expert when writing the reports.)
this is not the case when we consider more subjective classes such as, e.g., progresso, which describes the student's performance curve throughout the term (e.g., rising, falling, U-shaped etc.