Every work is prone to some or the other error, and unless efforts are made to avoid these errors a document or a piece of work cannot be error free. One can avoid errors only when one identifies the errors. Here is a quick guideline of errors that are more or less inevitable in a dissertation unless care is taken to avoid them.
Loss of focus:
By the time dissertations are written, one has already done a considerable amount of literature review, and there is a lot of knowledge that has been gathered. Far too often students flood out all the information collected and end up writing several pages without actually precisely mentioning; or converging the focus on their specific area.
Failing to highlight the importance of the work:
Committees in front of whom you defend your work are a learned group; and are interested in knowing why or the reason for spending years in doing the specific research. Also how is the work different from the existing work; and the justification of using the research fund?
Defending the choice of method and approach used:
Almost always there are several choices in methods available and the approach towards the research. Thus it is important to justify why a method or approach was followed and emphatically share your point of view.
Demarcating your research from that of the existing researches:
Each research grows on a previously existing research work, it is thus important to demarcate the exact areas of your research so that it is evident that this is a novel work and not a mere emulation of an existing work.
Clearly identifying your contributions:
Students often fail to stress on the contributions made by them in the present work, however this is the most critical aspect of a dissertation.
Proofreading and consistency in the dissertation document:
Most dissertations lose their impact due to the innumerable errors in language, typographical errors, indexing, and bibliography. For a document to be authentic, these are extremely important points to be remembered.