Although it may seem counter-intuitive, writing your introduction first may be more difficult to accomplish than starting with the meat of your paper. Starting by writing the main points (focusing on supporting your thesis) allows you to slightly change and manipulate your ideas and commentary.
Most research papers begin with a thesis statement at the end of an introductory paragraph. Even if it’s not a requirement, it’s a good idea to write a thesis statement as you begin to organize your research. Writing the thesis statement first is helpful because every argument or point you make in your paper should support this central idea you’re putting forward.
An argumentative research paper takes a position on a contentious issue and argues for one point of view. The issue should be debatable with a logical counter argument.
A single main point doesn’t have to be kept to a single paragraph, especially if you are writing a relatively long research paper. Main ideas can be spread out over as many paragraphs as you deem necessary.