A well researched dissertation will be very hard for anyone to refute. The aim of performing a research is to discover through testing a hypotheses or an idea. So a well researched dissertation is guaranteed to be accepted because of the fact that it is "well researched". Dissertations are meant for students to self learn and develop a conclusion accordingly.
A well researched dissertation will prove the finding of new knowledge which will result in the understanding of a new school of thought and even innovate or improve existing methodologies. A well researched dissertation should be developed to present and prove the results or hypothesis as well as provide a platform on which other scholars can further investigate the subject. In order to develop a well researched dissertation you must support your claim or hypothesis with facts, experiments and logic based deductions. Initially while developing a well researched dissertation first you have to analyze the data available on your topic. This will allow you to increase your knowledge base, identify any inconsistencies and eventually come up with a hypothesis that you will defend which in turn will result in the culmination of your well researched dissertation.
In order to develop a well researched dissertation you have to make sure that all the sources of information you use are approved by your governing education body and are factual. If you can prove your hypothesis through experiments, surveys, interviews and other forms of evidentiary data you will develop a well researched dissertation that no one will be able to refute and you will be recognized for your findings.