The expository essay is a category of essays that include subgenres such as an illustration essay, a cause and effect essay, and a process analysis essay. Expository essays have as their primary purpose the close examination of an activity or concept that can be taught or explained to a reader. A well-written expository essay typically begins with an introductory paragraph that contains a thesis statement followed by several body paragraphs and ends with a concluding paragraph.
Illustration essays use vignettes or other specific, briefly visited examples to clarify or enhance the paper’s purpose. For example, an illustration essay that explores the benefits of eating organic produce might briefly discuss an individual who has gained control over a health issue and ascribes it to a change to a more healthful diet. Through the use of a written "visual aid," the point can be made clearly and directly.
Another type of expository paper is cause and effect. This genre can focus on the reasons a particular situation exists or on the effects that it has on other things. Some papers combine the two, addressing both the causes and effects. A paper that explores the reasons for teenage drug abuse and the likely results if the abuse is not controlled is an example of the latter.
Process analysis essays are expository papers that explain something that must be done in a series of interrelated steps. Oftentimes, a process analysis paper teaches the reader how to do something, such as change engine oil or plant a wildflower garden. A process analysis expository essay that is too broad, such as one that describes how to repair all types of appliances, cannot go into sufficient detail to be useful; one that is too narrow, such as a paper that explains how to repair a carrot peeler, will be too narrow to draw many readers.
This type of academic paper isn’t designed to argue an idea or to compare two ideas or events. Its ultimate purpose is to teach the reader by offering new information or examining and clarifying something the reader knows a little about. A travel piece about a small village in Honduras could be the subject of an expository essay as could a close examination of the Battle of the Bulge or explanation of how to score the greatest number of points playing solitaire. An essay that delves into biology, such as the life cycle of frogs, is a further example.