A test that I had taken is a objective test. It only measures the aptitude of the student of picking the right answer from the given choice. There can be different tests like subjective test, open book test, surprise test, presentation on a particular subject, debate etc. Different test would give different scores for the same material.
Surprise test and presentations are commonly used as punishing mechanism by the teacher. It makes students more attentive in the class. In case of making a presentation students have to come prepared to attend the class. This leads to the students being more informed about the subject before the start of the class. It also leads to better participation of students in terms of discussion about the subject. It leads to students being more involved in the class.
There has to be a measure of performance, grades are one of the measure of performance (Afzaal, 2012). Accuracy of measurement might vary. At times grades measure the memory of the student rather that the understanding of the subject. In case of subjective exams grades are only a measure memory. Objective exam is a measure of picking the right options and time management. It might not be the measure of understanding of the subject. Presentations at times measure the speaking qualities of the student not the exact understanding. There are also different types of grades. Relative grading system tells how good one is against the population who has attempted the exam. It does not measure the absolute understanding of the subject.
Stakes of tests have become very high and most of these high stake tests are objective and relative grading system (Moses & Nanna, 2007). It will be difficult to say that it has improved the education system, but it has increase the level of competition among the students. These days tests are more of rejection mechanism rather that selection mechanism.
References
Afzaal, A. (2012). Grading and Its Discontents. The Chronicle of Higher Education. Retrieved from http://chronicle.com/article/GradingIts-Discontents/132789/
Moses, M.S. & Nanna, M.J. (2007). The Testing Culture and the Persistence of
High Stakes Testing Reforms. Education and Culture, 23 (1), pp. 55–72.
