One of the most difficult objectives for teachers is to ensure that all their students are engaged enough for effective learning. All students are different and each student may have an individual learning style. While it can be all but impossible to engage every student, every time, in every lesson, it is possible to discover the best method of engagement for most lessons and so impart the greatest amount of learning.
One useful method for teachers are Assessment Tests, which show the base knowledge of the student in the specified subject. Some students might come in with more knowledge than others; if the majority of students are ignorant of the subject, it might be better to focus on basics even if a minority of students are past that level. Similarly, if the majority of students have above-average knowledge in the subject, high-level lessons might be more useful, while lower-level students would benefit from individualized tutoring.
With that said, an Assessment Test will not give all the necessary information on a student to tailor individual assignments or lessons. It is equally necessary for a teacher to engage each student directly, either before or after the test, to gain an understanding of what is of interest, and so what will be retained and what will be forgotten. Here, the tests can be useful as jumping-off points to start conversation and discussion; a group of students with different opinions might have a class debate, moderated by the teacher and informed by their answers on the test.
Another use of Assessment Testing is to inform the school of their student body's knowledge demographics. With an understanding of the student body's strengths and weaknesses, the school board can create customized lesson plans or focus funding or manpower on a specific subject. If most of the students have a solid background in math, the school as a whole can focus on other subjects to increase those scores, while also helping the minority of students who struggle with math. By giving an idea of where effort would be most useful, the school can partition its resources more efficiently.