The reason for this is that I do not want to know whose it is when I am grading it. This prevents biased grading. One thing I do that makes the students remember the material better is I always make my final exams comprehensive. I have the last test close to the final, so that they have been tested on all but one class' worth of material. Since the students know that they may see the same topic on the final, they learn it better in the first place.
Egyptian students appear to believe that the topics covered in class and on tests are negotiable.
That does not occur in my classes because it is illogical. Another thing that I do to help the students is to encourage them to seek help from me. I do this many ways. First, I have them call me Wilf. To further encourage the students to seek help, I have nine hours of office hours a week instead of the two hours that the school requires.