Expository essays typically fall into three categories: process, summary and definition. The process essay tells readers how to accomplish a task. It might explain how to shoot free throws, bake a cake or buy a television. Summaries, such as book reports and research papers, highlight the important points of larger pieces of writing. A definition describes a concept by listing its characteristics, features and examples. For example, it might clarify the similarities and differences between private and public schools, or the reasons a child develops asthma.
When writing an expository paper, assume the reader has no background knowledge. This is particularly important when presenting multiple steps necessary to perform a task, since the reader might be following your directions to accomplish an undertaking. To ensure understanding, use simple, straightforward language and organize the information into a logical sequence. Incorporate sentences and ideas that show --- rather than tell --- the reader about your topic. Graphic organizers, such as Venn diagrams for cause-and-effect papers and timelines for process papers, often drive the outline of an expository essay.
Each expository writing format --- from compare-and-contrast essays to book reports --- requires vocabulary specific to its purpose. Cause-and-effect essays use phrases such as "in contrast" or "on the other hand." Transitional words --- such as "first," "next," "most importantly" and "then" --- are vital elements in sequencing and are used liberally in informational compositions. They move the reader from one step to the next. It is important to use transitional language at the beginning of each paragraph. Cause-and-effect papers make use of terms such as "therefore" and if-then constructions.
The first paragraph of an expository essay clearly introduces the subject of the paper in a topic sentence. The writer informs readers whether he will summarize, give directions, define or outline a process. The body paragraphs include important, rich facts, figures and examples to verify such things as possible causes and effects. Steps that must be taken to accomplish a task are arranged in a logical order. Every paragraph makes use of supporting details to further explain each step. The conclusion summarizes the steps.