To write a good thesis statement, the writer must evaluate the purpose of the written assignment, which may be to analyze, persuade, inform or evaluate. The writer must define the specifics of the topic and provide a specific claim or statement that summarizes the entire purpose of the topic in one sentence. The thesis statement serves as a road map for the reader and immediately establishes the writer's intentions.
If the essay is argumentative, the thesis statement should be debatable. The thesis serves as the primary focus and claim, clearly identifying the writer's position on the controversial issue. For example, thesis statements such as "Marijuana should be legalized in the United States" or "The drinking age should be lowered to 18 in the United States" indicate the writer's position on the topic and are debatable, as readers or interested parties may have opposing views.
A thesis statement for an informative paper introduces the topic to be detailed, such as the increase in homelessness in America. Analytical and evaluative essays often have a thesis statement that breaks down major parts of an issue or analyzes both sides of a controversial topic in a balanced and objective manner, according to Purdue University.