Please note: Some confusion may occur between the argumentative essay and the expository essay. These two genres are similar, but the argumentative essay differs from the expository essay in the amount of pre-writing invention and research involved. The argumentative essay is commonly assigned as a capstone or final project in first year writing or advanced composition courses and involves lengthy, detailed research. Expository essays involve less research and are shorter in length.
How to Write an Argumentative Essay (with Pictures) - wikiHow