For developing a dissertation, you are usually provided with several formatting guidelines by your supervisor or department. Many a times, these guidelines also include professional formats like APA, Chicago, Harvard, etc. If you feel that you can write a presentable dissertation anyhow, then you need to know the real importance of following professional formats.
There are commonly two reasons why you need to format your dissertation. One of these is to maintain the consistency of regular text, appearance and citations throughout your dissertation, as well as among several different dissertations. Formatting makes your dissertation actually look like a dissertation. The other reason is to make your content more tidy and readable for audience.