Each paragraph of the body of your research paper should be a cohesive unit. It should be tight, but developed. It should serve a function, and its purpose should always be to bolster the thesis. Therefore, you should use the following order for each paragraph in the body:
a.Topic sentence: This sentence summarizes the entire paragraph in one strong, well-written sentence, and it directly supports the thesis statement.
b.Explanation of topic sentence (1-2 sentences): Often times there is more to be said about the topic sentence, more explanation that is necessary in order for it to be a clear idea, so there are usually a few sentences that follow the topic sentence that explicate the idea more for the reader. These sentences not only "unpack" the topic sentence, but they also anticipate the evidence that will be used to support the topic sentence, usually indirectly.
c.Introduction to evidence (1-2 sentences): No piece of evidence (quotation, example, paraphrase, etc.) should be dropped into a paragraph without first introducing it. An introduction might include the title of the source, the author, and/or a short description of the source/author's credentials. In this way, no evidence is presented without a context because it is this context that makes the evidence meaningful.
Evidence: The evidence that you present backs up your topic sentence and, by extension, supports your thesis statement. The evidence that you supply can be a number of things: a quotation from a source; a reasonable, illustrative example; a statistic; commentary from an interview; etc.
e. Explanation of evidence: No piece of evidence stands on its own or is convincing on its own. Although it may seem to draw a direct line to your topic sentence to support it, often the reader needs you to make the connection between the two. Further, the general rule is that for each sentence of quoted material, your explanation should be just as long, so if you include a block quotation, the block quotation should be met with an equally long explanation.
f. Transition (1-2 sentences): Transitions are essential for research papers because body paragraphs, especially, are written as units, and it is the transitions that allow for these units to be linked together. Take a look at the list of transitional expressions on pp. 44-45 in The Little, Brown Compact Handbook with Exercises.