In an argument-based research project, the answer to your research question becomes your thesis, or central purpose for the essay. Your thesis should be reasonable, directed toward a specific audience, and be arguable—with a clear argument and clear counter-argument. Example of Research Question turned into a Thesis. Research Question.
For example, if the objective of your essay is to show the link between standardized test scores and learning foreign language in elementary level, your thesis statement should note this clearly. The importance of a thesis statement is that it helps the reader to identify the main idea of your education essay, because it reflects your opinion about the subject of writing.