Introductions for both essay styles should provide a context of why the given issue is relevant to discuss. However, the distinction between the two essay formats becomes visible with the main idea or thesis, which should state your central premise. For a research report, your main idea should objectively divulge the main issues and schools of thought that are pertinent to your subject. For a persuasive essay, your thesis should assert your subjective position in regard to your topic and introduce your basis for your argument. For example, a main idea for a research report on the school uniform debate might read: "While administrators assert that uniforms will strengthen academic performance and school safety, students argue that uniforms violate their right to express themselves as individuals." And a thesis on the same topic might read, "Although students value self-expression, the safety of their academic environments must come first."
Both essay styles call for comprehensive research for a complete sense of the facts and varying perspectives surrounding your topic. When compiling information for the research report, your goal is to use your sources to ensure that you're understanding and addressing the full scope of the issues at hand. When compiling information for the persuasive essay, your goal is to thoroughly consider every angle to not only decide how you feel about the issues at hand, but also to determine what evidence you can present to best defend your position -- as well as to anticipate potential counterarguments that could dismantle your thesis and its basis.
A thorough research report treats perspectives equally, pointing out central arguments and counterarguments concerning each, without suggesting bias toward either. Strengths and weaknesses of one perspective should be addressed as fully as strengths and weaknesses of any other. The persuasive essay's emphasis, however, is on exploiting the weaknesses of opposing perspectives and defending any element of its own perspective that could be perceived as a weakness. A thorough persuasive essay must protect its stance and strengthen its argument by anticipating potential counterarguments that could weaken its position, and refuting them preemptively.
Both essay styles must incorporate facts, but research reports take an investigative approach while persuasive essays take a more critical approach. Analysis presented in the persuasive essay may use more biased phrasing and may appeal to morals, ethics or emotions in an effort to convince. The research report simply presents all relevant information in an effort to inform. Research reports invite readers to draw their own conclusions based on all the facts. Persuasive essays are strategically organized to logically build up to how the writer came to his conclusion and to enlist readers to draw the same one -- including only the content that will contribute to that effort.