Hi George:
Fair is always a needed goal; achieving that is a bit harder. One way is assure that all course and student learning objectives have been adequately coved in the course, then keep the questions tied to the objectives - that will help remaining fair.
Using a grading rubric that is available at the beginning of a course is another effective tool. In this way, students know from the get go how the teacher will assigning grades. Smart students will learn to review the rubric and do their best to model their performance after the higher point categories.
Regards,… >>>