MBA aspirants note that in XAT 2013 you will be tested on Essay writing. The essay is used as a tool to judge the social and ethical values of the aspirant as the written piece provides a valuable insight into the mind of the test taker.
The B-schools use the essay as a pre-interview yardstick as well. The panel also judges your clarity of thoughts, logical hints, focus and concentration, etc. through your essay.
Structure, argument and several other factors that you portray through your essay is judged as well. Each of these factors reflects your personality traits and that is the main criteria for selection.
For instance, XAT essay would test you out on these parameters including the knowledge about the topic, so the interviewers would know some of your personality traits and can easily spot if you are lying to them or trying to depict what you are not.