I also bend my knees so I am at eye-level with the student to speak with him or her. I exemplify the type of courtesy I expect from my students. I also believe that there is no excuse for unequal consideration of human beings. While it can be difficult to accept extreme differences between people, I use my knowledge of these differences as a learning experience for my students as well as myself. The world would be a very boring place if we were all the same.
Students vary in background, ability, learning style, etc.
Therefore, I vary my instructional strategies to meet each student's needs. In one class, I have students who make all As and Bs, while two others cannot take a test without it being read to them. I make modifications in instruction and evaluation based on this knowledge. I consider individual needs when assessing learning and grades.