What is the difference between preparing a research proposal and writing the actual thesis in the case of theoretical research?

Question

In some countries, whenever someone applies for a Ph.D. admission, the universities ask for a research proposal. A research proposal includes a literature review and bibliography.

If the research is paper-based research, i.e. no popular survey or experiment is involved, I see no further need for research work. For instance, say, someone wants to redefine and redescribe the origin and purpose of British colonialism in India. In this case, if the researcher has already read the needed resources and done his desk-research, the only task left is writing a thesis that may take at most three months.

What is the difference between preparing a research proposal and writing the actual thesis in the case of theoretical research?

Answer 1

In general a research proposal (separate from the literature review) is a description of the questions that you wish to answer in the research and a description, perhaps preliminary, about how you intend to answer those questions. it doesn't include the results, which, we assume, aren't available yet.

The literature review asked for will probably be less complete than the one that later appears in the dissertation, since all that is needed here is the papers, etc, that you have read that lead you to ask the question and support the idea that they are important questions that haven't yet been answered. You will possibly need to do more in a formal literature review once the research begins.

You seem to imply in the question that all research questions have already been answered before you make the proposal. That is normally not the case. In the example you state, your proposal should also include how you intend to support the conclusions you reach. This might include additional library research or interviews with knowledgeable people, etc.

Answer 2

Even if we imagine that the information of interest is perfectly and unambiguously presented (which is not reliably the case...), it is absolutely NOT the case that all the logical implications are easily obtainable. (See K. Godel's completeness and incompleteness theorems, about first-order predicate logic.)

Another aspect: even though one can perhaps conceive of a project, and see no obstacles to its completion, that is very different from execution of the project. E.g., conceiving of moving a huge pile of sand from one spot to another, versus literally moving it.

And, also, there's the question of "what questions we didn't think to ask" :)