This essay will be a comparative essay; therefore, you need to think about how the novel and the film are similar or different.  Many points exist for comparison which means that you must choose three or four which are important and which you can develop with examples from both the novel and the film. How do they develop the theme?  Does the film use close-up shots or setting to help the viewer understand the theme? Do the characters in both the novel and the film show the theme in the same way?  How are the characters developed in both mediums?  What can the novel do with inner thoughts or conflict which the film cannot?  Do you plan to use only similarities, or do you plan to show the differences?  Which topics you choose to use is up to you; just make sure that you compare both mediums of novel and film because they can quite similar or quite different.