When writing a doctoral dissertation students should be aware of the fact that it should be assesses very carefully because of the fact that it is written for the highest academic level. That is the reason why it should be written with extreme care. Dissertations of all the levels should be written appropriately because of the fact that the final degree of the students is based on these dissertations. Doctoral dissertation is also known as PHD dissertation and they contain all the aspects of a dissertation. However, one of the core differences in these dissertations are they are extremely long and they are quite extensive too. Usually, a PHD dissertation consists of 25 to 50 thousand words and they can be even longer than that. They usually contain more chapters that the general dissertations and that is the reason why they are more difficult to write.