A research proposal is a comprehensive plan for a research project. It is a written description of a research plan that has to be undertaken. It determines the specific areas of research, states the purpose, scope, methodology, overall organization and limitations of the study.

In brief, a research proposal:-

• Is a document which determines whether a candidate is capable of carrying out independent research.
• Presents a problem, discusses related research efforts, outlines needed to solve the problems, and shows the design used to gather and analyze the data.
• It is a work plan, prospectus, outline, statement of intent, or draft plan.
• Tells the reader what, why, how, where, and to whom the research will be done and shows the benefit of doing research.
• Is used in most institutions as the main criterion to accept or reject a student’s candidacy.

Research proposals have multiple components. Of course, not all research proposals will look exactly like this. In general, your research proposal should contain the following:

1. The Introduction. The introduction should briefly introduce your research problem, and explain why you want to investigate it. 
2. The Research Question. The second part of your proposal should be an in-depth look at your research problem. You should explain why your research is important and investigate similar research in the field (if any is available). You will likely find that similar research exists, but is partially incomplete. You should demonstrate what is currently missing from the scholarly conversation, and explain why your research can "patch" this hole. 
3. The Methodology. The third part of your proposal should explain how you intend to conduct your research. Your proposal should answer the following questions:
   1. What research methods are appropriate in solving my research question?
   2. What method am I choosing and why? What are its benefits and drawbacks?
   3. What population am I testing? How am I ensuring a reliable control? 
   4. How can I ensure neutrality and consistency? How sound is my research?
   5. How does my research method applicably solve my research problem? 
4. The Logistics. After presenting your research methods, you should commit to a timetable. You should present a reasonable schedule and budget. Then, you should explain how you intend to stay on track with these limits. 
5. The Conclusion. Finally, you should concisely wrap up your proposal. In doing this, highlight the importance of your research once more. 

The following publication provides an overview on the importance of developing an effective research proposal. The book will help readers to understand the context within which their proposal will be read, what the reviewers are looking for and will be influenced by, while also supporting the development of relevant skills through advice and practical activities.

Useful links:

Research Tips (Penn State)

Sample Research Proposal (University of Houston)

Writing a Research Proposal (USC)

Developing Successful Research Questions (University of California, Merced)

Additionally, this video lays out the key elements of designing a research proposal: