The document provides guidance on writing an effective thesis statement. It defines a thesis statement as the main idea of an essay that presents the writer's opinion or argument. An effective thesis statement is usually one sentence, placed in the introductory paragraph. It should not include first person pronouns, unclear language, or attempt to address multiple topics. A good thesis statement contains a clear topic and opinion, is specific rather than too broad or wordy, and presents an argument rather than just stating a fact. Examples are provided to illustrate strong and weak thesis statements.