All three of these are stages in doing professional research. You can kind of think of it in architectural terms: sketches, blueprints, and finally building the house.
- Concept paper -- A concept paper is putting your idea onto paper. It includes what the question is, what is already known about that question, and why the question is worth expending energy on in the first place. It also typically includes information about areas that might be problematic from a research standpoint, and also a proposed list of sources. In a lot of ways, a concept paper is used to focus your thoughts and it might not be seen in an "official" way by anyone else.
- Research proposal -- This is the bit that actually can get a "green light" and allows a person to begin research. It is usually what would be examined by "experts" in an academic setting. It is more detailed than the concept paper because it has to prove that the research is needed, and it also has to detail the methods that are going to be used in collecting data. There is also typically an extensive "literature review" of what's already known about the topic.
- Research report -- This is actually doing the work of putting the report together. It includes your research and conclusions. It is the work that will either be accepted as valid or rejected by those who read it. A research report follows a strict outline and must be created with a high level of professionalism.
There is a difference between a concept paper, a research proposal, and a research report. A concept paper usually reflects an issue that is of interest to a writer. The paper provides an opportunity to have a deep discussion about the specific issue or issues. The concept paper may advocate for certain ideas or policies to be followed.
A research proposal is an attempt to get permission and/or funding to pursue a project that is of interest to the individual making the proposal. This proposal should include the what, why, and how of the project. The author should state what they are going to do, how they are going to do it, and why they want to do it.
The research report is the actual paper or project that shows the results of a person’s research. This is often presented in a formal setting and may be used to grant the author an advanced degree. The report should include an introduction, a review of the literature, an explanation of methods that were used, the results that were obtained, and a discussion of findings.