Essay questions should be carefully worded so as to address specific instructional objectives. Also, you must be clear on the amount of detail you expect, either by itemizing points to be covered or suggesting an appropriate length for the answer.
As mentioned above, essay tests are difficult to score. The best sounding question may turn out to be a nightmare to score. On your scoring key, you need to have a list of specific facts or lines of reasoning or examples of style that you’ll be looking for in each answer. It must assign a point value to each item. Their letter grade is based on the point total. You want as little subjectivity in the scoring as possible.
Another decision you’ll have to make before announcing the test is the extent to which you will score spelling, grammar and form. If these factors could constitute a large portion of the grade, it would be best to give two grades, one for content and the other for mechanics.
Go to “Constructing Matching Tests“