Expository writing tells all
And it is found everywhere

Almost all written material ordinary people read and write is exposition.

Memos, emails, letters to the editor, notes to Kyle's teacher — all are examples of exposition. So are Kyle's algebra text, your employee manual, and the daily paper.

Each of those forms of writing is an example of nonfiction informative prose. In each case the writing exposes or explains opinions or ideas.

It is non or not fiction because the writers present it as true and believe that it is true. They may be mistaken, but that's a different matter.

Good exposition does for ideas what supermarket tabloids for celebrities' bodies: lays them out where nobody can miss a freckle on them.

Exposition can occur in both fiction and nonfiction, but the term expository writing refers only to nonfiction. The ELA curriculum is full of such terminology traps for unwary teachers and students.

More about writing nonfiction info

Definitions and other background information that teachers with minimal formal English study may find useful are found elsewhere on this thread:

• What nonfiction isn't

• What nonfiction is

• Nonfiction doesn't have elements comparable to "elements of fiction"

• Informal writing can help you teach formal writing skills

• Critical thinking strategies are the foundation of substantive writing

• How writing can teach critical thinking strategies.

• Logical order options for exposition

• Alphabetical order

• Numerical order

• Chronological order

• Spatial order

• Inverted pyramid order

• Emphatic order as seen in persuasive writing

Although the word expository often suggests lengthy pieces of writing, the skills needed to write expository nonfiction can be developed through short pieces of writing. My book Shape Learning, Reshape Teaching shows how to use informal writing as a tool for learning and formative assessment while simultaneously giving students opportunities to practice writing skills.