The main purpose of a dissertation proposal is to prove each of the following:
the problem is significant enough to warrant investigation;
the method one plans to use is suitable and feasible;
the results are likely to be fruitful and will make an original contribution.
The dissertation proposal will provide a general idea of what the dissertation writer is proposing to research, but it does not have to be a final, binding commitment. It can serve as a starting point for discussions with the writer's supervisor about topic, methodology, and mechanics of research.
While the structure of a standard proposal is not set in stone, a typical proposal includes the following:
aims and objectives
significance
review of previous research in the area and justification for further research
proposed methods
expected outcomes and their importance
requirements for equipment, materials, field trips, and funding (if applicable)
approximate time by which each stage will be completed
The length of the writer's dissertation proposal can range from 3-4 pages to 30-40 pages, depending on the requirements of a particular department in a particular university.
